diff --git a/deploy/product.sql b/deploy/product.sql
index 7ddef6a..5d6232c 100644
--- a/deploy/product.sql
+++ b/deploy/product.sql
@@ -14,7 +14,6 @@ create table product (
 	name text not null,
 	description text not null,
 	price integer not null,
-	tax_id integer not null references tax,
 	created_at timestamptz not null default current_timestamp
 );
 
diff --git a/deploy/product_tax.sql b/deploy/product_tax.sql
new file mode 100644
index 0000000..7188f8a
--- /dev/null
+++ b/deploy/product_tax.sql
@@ -0,0 +1,31 @@
+-- Deploy numerus:product_tax to pg
+-- requires: schema_numerus
+-- requires: product
+-- requires: tax
+
+begin;
+
+set search_path to numerus, public;
+
+create table product_tax (
+	product_id integer not null references product,
+	tax_id integer not null references tax,
+	primary key (product_id, tax_id)
+);
+
+grant select, insert, update, delete on table product_tax to invoicer;
+grant select, insert, update, delete on table product_tax to admin;
+
+alter table product_tax enable row level security;
+
+create policy company_policy
+on product_tax
+using (
+	exists(
+		select 1
+		from product
+		where product.product_id = product_tax.product_id
+	)
+);
+
+commit;
diff --git a/pkg/company.go b/pkg/company.go
index 146c8ac..ded4f0c 100644
--- a/pkg/company.go
+++ b/pkg/company.go
@@ -89,7 +89,7 @@ func newTaxDetailsForm(ctx context.Context, conn *Conn, locale *Locale) *taxDeta
 			Label:    pgettext("input", "Currency", locale),
 			Options:  MustGetOptions(ctx, conn, "select currency_code, currency_symbol from currency order by currency_code"),
 			Required: true,
-			Selected: "EUR",
+			Selected: []string{"EUR"},
 		},
 	}
 }
diff --git a/pkg/contacts.go b/pkg/contacts.go
index ed44982..bd0f1bc 100644
--- a/pkg/contacts.go
+++ b/pkg/contacts.go
@@ -222,10 +222,10 @@ func newContactForm(ctx context.Context, conn *Conn, locale *Locale) *contactFor
 		},
 		Country: &SelectField{
 			Name:     "country",
-			Label:    pgettext("input", "Tax", locale),
+			Label:    pgettext("input", "Country", locale),
 			Options:  mustGetCountryOptions(ctx, conn, locale),
 			Required: true,
-			Selected: "ES",
+			Selected: []string{"ES"},
 			Attributes: []template.HTMLAttr{
 				`autocomplete="country"`,
 			},
@@ -253,12 +253,18 @@ func (form *contactForm) Parse(r *http.Request) error {
 
 func (form *contactForm) Validate(ctx context.Context, conn *Conn) bool {
 	validator := newFormValidator()
+
+	country := ""
+	if validator.CheckValidSelectOption(form.Country, gettext("Selected country is not valid.", form.locale)) {
+		country = form.Country.Selected[0]
+	}
+
 	validator.CheckRequiredInput(form.BusinessName, gettext("Business name can not be empty.", form.locale))
 	if validator.CheckRequiredInput(form.VATIN, gettext("VAT number can not be empty.", form.locale)) {
-		validator.CheckValidVATINInput(form.VATIN, form.Country.Selected, gettext("This value is not a valid VAT number.", form.locale))
+		validator.CheckValidVATINInput(form.VATIN, country, gettext("This value is not a valid VAT number.", form.locale))
 	}
 	if validator.CheckRequiredInput(form.Phone, gettext("Phone can not be empty.", form.locale)) {
-		validator.CheckValidPhoneInput(form.Phone, form.Country.Selected, gettext("This value is not a valid phone number.", form.locale))
+		validator.CheckValidPhoneInput(form.Phone, country, gettext("This value is not a valid phone number.", form.locale))
 	}
 	if validator.CheckRequiredInput(form.Email, gettext("Email can not be empty.", form.locale)) {
 		validator.CheckValidEmailInput(form.Email, gettext("This value is not a valid email. It should be like name@domain.com.", form.locale))
@@ -270,8 +276,7 @@ func (form *contactForm) Validate(ctx context.Context, conn *Conn) bool {
 	validator.CheckRequiredInput(form.City, gettext("City can not be empty.", form.locale))
 	validator.CheckRequiredInput(form.Province, gettext("Province can not be empty.", form.locale))
 	if validator.CheckRequiredInput(form.PostalCode, gettext("Postal code can not be empty.", form.locale)) {
-		validator.CheckValidPostalCode(ctx, conn, form.PostalCode, form.Country.Selected, gettext("This value is not a valid postal code.", form.locale))
+		validator.CheckValidPostalCode(ctx, conn, form.PostalCode, country, gettext("This value is not a valid postal code.", form.locale))
 	}
-	validator.CheckValidSelectOption(form.Country, gettext("Selected country is not valid.", form.locale))
 	return validator.AllOK()
 }
diff --git a/pkg/db.go b/pkg/db.go
index 232320a..6c59468 100644
--- a/pkg/db.go
+++ b/pkg/db.go
@@ -70,6 +70,14 @@ type Conn struct {
 	*pgxpool.Conn
 }
 
+func (c *Conn) MustBegin(ctx context.Context) *Tx {
+	tx, err := c.Begin(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return &Tx{tx}
+}
+
 func (c *Conn) MustGetText(ctx context.Context, def string, sql string, args ...interface{}) string {
 	var result string
 	if err := c.Conn.QueryRow(ctx, sql, args...).Scan(&result); err != nil {
@@ -87,3 +95,46 @@ func (c *Conn) MustExec(ctx context.Context, sql string, args ...interface{}) {
 		panic(err)
 	}
 }
+
+type Tx struct {
+	pgx.Tx
+}
+
+func (tx *Tx) MustCommit(ctx context.Context) {
+	if err := tx.Commit(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (tx *Tx) MustRollback(ctx context.Context) {
+	if err := tx.Rollback(ctx); err != nil {
+		panic(err)
+	}
+}
+
+func (tx *Tx) MustGetInteger(ctx context.Context, sql string, args ...interface{}) int {
+	var result int
+	if err := tx.QueryRow(ctx, sql, args...).Scan(&result); err != nil {
+		panic(err)
+	}
+	return result
+}
+
+func (tx *Tx) MustGetIntegerOrDefault(ctx context.Context, def int, sql string, args ...interface{}) int {
+	var result int
+	if err := tx.QueryRow(ctx, sql, args...).Scan(&result); err != nil {
+		if err == pgx.ErrNoRows {
+			return def
+		}
+		panic(err)
+	}
+	return result
+}
+
+func (tx *Tx) MustCopyFrom(ctx context.Context, tableName string, columns []string, rows [][]interface{}) int64 {
+	copied, err := tx.CopyFrom(ctx, pgx.Identifier{tableName}, columns, pgx.CopyFromRows(rows))
+	if err != nil {
+		panic(err)
+	}
+	return copied
+}
diff --git a/pkg/form.go b/pkg/form.go
index ca0dfbc..adcc407 100644
--- a/pkg/form.go
+++ b/pkg/form.go
@@ -58,34 +58,56 @@ type SelectOption struct {
 type SelectField struct {
 	Name       string
 	Label      string
-	Selected   string
+	Selected   []string
 	Options    []*SelectOption
 	Attributes []template.HTMLAttr
 	Required   bool
+	Multiple   bool
 	EmptyLabel string
 	Errors     []error
 }
 
 func (field *SelectField) Scan(value interface{}) error {
 	if value == nil {
-		field.Selected = ""
+		field.Selected = append(field.Selected, "")
 		return nil
 	}
-	field.Selected = fmt.Sprintf("%v", value)
+	field.Selected = append(field.Selected, fmt.Sprintf("%v", value))
 	return nil
 }
 
 func (field *SelectField) Value() (driver.Value, error) {
-	return field.Selected, nil
+	if field.Selected == nil {
+		return "", nil
+	}
+	return field.Selected[0], nil
 }
 
 func (field *SelectField) FillValue(r *http.Request) {
-	field.Selected = r.FormValue(field.Name)
+	field.Selected = r.Form[field.Name]
 }
 
-func (field *SelectField) HasValidOption() bool {
+func (field *SelectField) HasValidOptions() bool {
+	for _, selected := range field.Selected {
+		if !field.isValidOption(selected) {
+			return false
+		}
+	}
+	return true
+}
+
+func (field *SelectField) IsSelected(v string) bool {
+	for _, selected := range field.Selected {
+		if selected == v {
+			return true
+		}
+	}
+	return false
+}
+
+func (field *SelectField) isValidOption(selected string) bool {
 	for _, option := range field.Options {
-		if option.Value == field.Selected {
+		if option.Value == selected {
 			return true
 		}
 	}
@@ -155,7 +177,7 @@ func (v *FormValidator) CheckPasswordConfirmation(password *InputField, confirm
 }
 
 func (v *FormValidator) CheckValidSelectOption(field *SelectField, message string) bool {
-	return v.checkSelect(field, field.HasValidOption(), message)
+	return v.checkSelect(field, field.HasValidOptions(), message)
 }
 
 func (v *FormValidator) checkValidURL(field *InputField, message string) bool {
diff --git a/pkg/products.go b/pkg/products.go
index 7877ed4..263b6c3 100644
--- a/pkg/products.go
+++ b/pkg/products.go
@@ -36,12 +36,12 @@ func GetProductForm(w http.ResponseWriter, r *http.Request, params httprouter.Pa
 	form := newProductForm(r.Context(), conn, locale, company)
 	slug := params[0].Value
 	if slug == "new" {
-		form.Tax.EmptyLabel = gettext("Select a tax for this product.", locale)
 		w.WriteHeader(http.StatusOK)
 		mustRenderNewProductForm(w, r, form)
 		return
 	}
-	err := conn.QueryRow(r.Context(), "select product.name, product.description, to_price(price, decimal_digits), tax_id from product join company using (company_id) join currency using (currency_code) where product.slug = $1", slug).Scan(form.Name, form.Description, form.Price, form.Tax)
+	var productId int
+	err := conn.QueryRow(r.Context(), "select product_id, product.name, product.description, to_price(price, decimal_digits) from product join company using (company_id) join currency using (currency_code) where product.slug = $1", slug).Scan(&productId, form.Name, form.Description, form.Price)
 	if err != nil {
 		if err == pgx.ErrNoRows {
 			http.NotFound(w, r)
@@ -50,6 +50,16 @@ func GetProductForm(w http.ResponseWriter, r *http.Request, params httprouter.Pa
 			panic(err)
 		}
 	}
+	rows, err := conn.Query(r.Context(), "select tax_id from product_tax where product_id = $1", productId)
+	if err != nil {
+		panic(err)
+	}
+	defer rows.Close()
+	for rows.Next() {
+		if err := rows.Scan(form.Tax); err != nil {
+			panic(err)
+		}
+	}
 	w.WriteHeader(http.StatusOK)
 	mustRenderEditProductForm(w, r, form)
 }
@@ -79,7 +89,24 @@ func HandleAddProduct(w http.ResponseWriter, r *http.Request, _ httprouter.Param
 		mustRenderNewProductForm(w, r, form)
 		return
 	}
-	conn.MustExec(r.Context(), "insert into product (company_id, name, description, price, tax_id) select company_id, $2, $3, parse_price($4, decimal_digits), $5 from company join currency using (currency_code) where company_id = $1", company.Id, form.Name, form.Description, form.Price, form.Tax)
+	tx := conn.MustBegin(r.Context())
+	productId := tx.MustGetInteger(r.Context(), "insert into product (company_id, name, description, price) select company_id, $2, $3, parse_price($4, decimal_digits) from company join currency using (currency_code) where company_id = $1 returning product_id", company.Id, form.Name, form.Description, form.Price)
+	if len(form.Tax.Selected) > 0 {
+		batch := &pgx.Batch{}
+		for _, tax := range form.Tax.Selected {
+			batch.Queue("insert into product_tax(product_id, tax_id) values ($1, $2)", productId, tax)
+		}
+		br := tx.SendBatch(r.Context(), batch)
+		for range form.Tax.Selected {
+			if _, err := br.Exec(); err != nil {
+				panic(err)
+			}
+		}
+		if err := br.Close(); err != nil {
+			panic(err)
+		}
+	}
+	tx.MustCommit(r.Context())
 	http.Redirect(w, r, companyURI(company, "/products"), http.StatusSeeOther)
 }
 
@@ -100,10 +127,28 @@ func HandleUpdateProduct(w http.ResponseWriter, r *http.Request, params httprout
 		mustRenderEditProductForm(w, r, form)
 		return
 	}
-	slug := conn.MustGetText(r.Context(), "", "update product set name = $1, description = $2, price = parse_price($3, decimal_digits), tax_id = $4 from company join currency using (currency_code) where product.company_id = company.company_id and product.slug = $5 returning product.slug", form.Name, form.Description, form.Price, form.Tax, params[0].Value)
-	if slug == "" {
+	tx := conn.MustBegin(r.Context())
+	slug := params[0].Value
+	productId := tx.MustGetIntegerOrDefault(r.Context(), 0, "update product set name = $1, description = $2, price = parse_price($3, decimal_digits) from company join currency using (currency_code) where product.company_id = company.company_id and product.slug = $4 returning product_id", form.Name, form.Description, form.Price, slug)
+	if productId == 0 {
+		tx.MustRollback(r.Context())
 		http.NotFound(w, r)
 	}
+	batch := &pgx.Batch{}
+	batch.Queue("delete from product_tax where product_id = $1", productId)
+	for _, tax := range form.Tax.Selected {
+		batch.Queue("insert into product_tax(product_id, tax_id) values ($1, $2)", productId, tax)
+	}
+	br := tx.SendBatch(r.Context(), batch)
+	for i := 0; i < batch.Len(); i++ {
+		if _, err := br.Exec(); err != nil {
+			panic(err)
+		}
+	}
+	if err := br.Close(); err != nil {
+		panic(err)
+	}
+	tx.MustCommit(r.Context())
 	http.Redirect(w, r, companyURI(company, "/products/"+slug), http.StatusSeeOther)
 }
 
@@ -166,8 +211,8 @@ func newProductForm(ctx context.Context, conn *Conn, locale *Locale, company *Co
 		},
 		Tax: &SelectField{
 			Name:     "tax",
-			Label:    pgettext("input", "Tax", locale),
-			Required: true,
+			Label:    pgettext("input", "Taxes", locale),
+			Multiple: true,
 			Options:  MustGetOptions(ctx, conn, "select tax_id::text, name from tax where company_id = $1 order by name", company.Id),
 		},
 	}
diff --git a/pkg/profile.go b/pkg/profile.go
index f91e2b1..eb33bca 100644
--- a/pkg/profile.go
+++ b/pkg/profile.go
@@ -102,7 +102,7 @@ func GetProfileForm(w http.ResponseWriter, r *http.Request, _ httprouter.Params)
 	form := newProfileForm(r.Context(), conn, locale)
 	form.Name.Val = conn.MustGetText(r.Context(), "", "select name from user_profile")
 	form.Email.Val = user.Email
-	form.Language.Selected = user.Language.String()
+	form.Language.Selected = []string{user.Language.String()}
 
 	w.WriteHeader(http.StatusOK)
 	mustRenderProfileForm(w, r, form)
diff --git a/po/ca.po b/po/ca.po
index d5b4aca..fb5b368 100644
--- a/po/ca.po
+++ b/po/ca.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: numerus\n"
 "Report-Msgid-Bugs-To: jordi@tandem.blog\n"
-"POT-Creation-Date: 2023-02-05 14:04+0100\n"
+"POT-Creation-Date: 2023-02-08 13:43+0100\n"
 "PO-Revision-Date: 2023-01-18 17:08+0100\n"
 "Last-Translator: jordi fita mas <jordi@tandem.blog>\n"
 "Language-Team: Catalan <ca@dodds.net>\n"
@@ -238,11 +238,11 @@ msgctxt "input"
 msgid "Password"
 msgstr "Contrasenya"
 
-#: pkg/login.go:69 pkg/profile.go:89 pkg/contacts.go:263
+#: pkg/login.go:69 pkg/profile.go:89 pkg/contacts.go:269
 msgid "Email can not be empty."
 msgstr "No podeu deixar el correu-e en blanc."
 
-#: pkg/login.go:70 pkg/profile.go:90 pkg/contacts.go:264
+#: pkg/login.go:70 pkg/profile.go:90 pkg/contacts.go:270
 msgid "This value is not a valid email. It should be like name@domain.com."
 msgstr "Aquest valor no és un correu-e vàlid. Hauria de ser similar a nom@domini.cat."
 
@@ -254,43 +254,39 @@ msgstr "No podeu deixar la contrasenya en blanc."
 msgid "Invalid user or password."
 msgstr "Nom d’usuari o contrasenya incorrectes."
 
-#: pkg/products.go:39
-msgid "Select a tax for this product."
-msgstr "Escolliu un impost per aquest producte."
-
-#: pkg/products.go:148
+#: pkg/products.go:193
 msgctxt "input"
 msgid "Name"
 msgstr "Nom"
 
-#: pkg/products.go:154
+#: pkg/products.go:199
 msgctxt "input"
 msgid "Description"
 msgstr "Descripció"
 
-#: pkg/products.go:159
+#: pkg/products.go:204
 msgctxt "input"
 msgid "Price"
 msgstr "Preu"
 
-#: pkg/products.go:169 pkg/contacts.go:225
+#: pkg/products.go:214
 msgctxt "input"
-msgid "Tax"
-msgstr "Impost"
+msgid "Taxes"
+msgstr "Imposts"
 
-#: pkg/products.go:189 pkg/profile.go:92
+#: pkg/products.go:234 pkg/profile.go:92
 msgid "Name can not be empty."
 msgstr "No podeu deixar el nom en blanc."
 
-#: pkg/products.go:190
+#: pkg/products.go:235
 msgid "Price can not be empty."
 msgstr "No podeu deixar el preu en blanc."
 
-#: pkg/products.go:191
+#: pkg/products.go:236
 msgid "Price must be a number greater than zero."
 msgstr "El preu ha de ser un número major a zero."
 
-#: pkg/products.go:193
+#: pkg/products.go:238
 msgid "Selected tax is not valid."
 msgstr "Heu seleccionat un impost que no és vàlid."
 
@@ -398,57 +394,65 @@ msgctxt "input"
 msgid "Postal code"
 msgstr "Codi postal"
 
-#: pkg/contacts.go:256
-msgid "Business name can not be empty."
-msgstr "No podeu deixar el nom i els cognoms en blanc."
-
-#: pkg/contacts.go:257
-msgid "VAT number can not be empty."
-msgstr "No podeu deixar el DNI o NIF en blanc."
+#: pkg/contacts.go:225
+msgctxt "input"
+msgid "Country"
+msgstr "País"
 
 #: pkg/contacts.go:258
-msgid "This value is not a valid VAT number."
-msgstr "Aquest valor no és un DNI o NIF vàlid."
-
-#: pkg/contacts.go:260
-msgid "Phone can not be empty."
-msgstr "No podeu deixar el telèfon en blanc."
-
-#: pkg/contacts.go:261
-msgid "This value is not a valid phone number."
-msgstr "Aquest valor no és un telèfon vàlid."
-
-#: pkg/contacts.go:267
-msgid "This value is not a valid web address. It should be like https://domain.com/."
-msgstr "Aquest valor no és una adreça web vàlida. Hauria de ser similar a https://domini.cat/."
-
-#: pkg/contacts.go:269
-msgid "Address can not be empty."
-msgstr "No podeu deixar l’adreça en blanc."
-
-#: pkg/contacts.go:270
-msgid "City can not be empty."
-msgstr "No podeu deixar la població en blanc."
-
-#: pkg/contacts.go:271
-msgid "Province can not be empty."
-msgstr "No podeu deixar la província en blanc."
-
-#: pkg/contacts.go:272
-msgid "Postal code can not be empty."
-msgstr "No podeu deixar el codi postal en blanc."
-
-#: pkg/contacts.go:273
-msgid "This value is not a valid postal code."
-msgstr "Aquest valor no és un codi postal vàlid."
-
-#: pkg/contacts.go:275
 msgid "Selected country is not valid."
 msgstr "Heu seleccionat un país que no és vàlid."
 
+#: pkg/contacts.go:262
+msgid "Business name can not be empty."
+msgstr "No podeu deixar el nom i els cognoms en blanc."
+
+#: pkg/contacts.go:263
+msgid "VAT number can not be empty."
+msgstr "No podeu deixar el DNI o NIF en blanc."
+
+#: pkg/contacts.go:264
+msgid "This value is not a valid VAT number."
+msgstr "Aquest valor no és un DNI o NIF vàlid."
+
+#: pkg/contacts.go:266
+msgid "Phone can not be empty."
+msgstr "No podeu deixar el telèfon en blanc."
+
+#: pkg/contacts.go:267
+msgid "This value is not a valid phone number."
+msgstr "Aquest valor no és un telèfon vàlid."
+
+#: pkg/contacts.go:273
+msgid "This value is not a valid web address. It should be like https://domain.com/."
+msgstr "Aquest valor no és una adreça web vàlida. Hauria de ser similar a https://domini.cat/."
+
+#: pkg/contacts.go:275
+msgid "Address can not be empty."
+msgstr "No podeu deixar l’adreça en blanc."
+
+#: pkg/contacts.go:276
+msgid "City can not be empty."
+msgstr "No podeu deixar la població en blanc."
+
+#: pkg/contacts.go:277
+msgid "Province can not be empty."
+msgstr "No podeu deixar la província en blanc."
+
+#: pkg/contacts.go:278
+msgid "Postal code can not be empty."
+msgstr "No podeu deixar el codi postal en blanc."
+
+#: pkg/contacts.go:279
+msgid "This value is not a valid postal code."
+msgstr "Aquest valor no és un codi postal vàlid."
+
+#~ msgid "Select a tax for this product."
+#~ msgstr "Escolliu un impost per aquest producte."
+
 #~ msgctxt "input"
-#~ msgid "Country"
-#~ msgstr "País"
+#~ msgid "Tax"
+#~ msgstr "Impost"
 
 #~ msgctxt "nav"
 #~ msgid "Customers"
diff --git a/po/es.po b/po/es.po
index 01e5c9e..cbd9f11 100644
--- a/po/es.po
+++ b/po/es.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: numerus\n"
 "Report-Msgid-Bugs-To: jordi@tandem.blog\n"
-"POT-Creation-Date: 2023-02-05 14:04+0100\n"
+"POT-Creation-Date: 2023-02-08 13:43+0100\n"
 "PO-Revision-Date: 2023-01-18 17:45+0100\n"
 "Last-Translator: jordi fita mas <jordi@tandem.blog>\n"
 "Language-Team: Spanish <es@tp.org.es>\n"
@@ -238,11 +238,11 @@ msgctxt "input"
 msgid "Password"
 msgstr "Contraseña"
 
-#: pkg/login.go:69 pkg/profile.go:89 pkg/contacts.go:263
+#: pkg/login.go:69 pkg/profile.go:89 pkg/contacts.go:269
 msgid "Email can not be empty."
 msgstr "No podéis dejar el correo-e en blanco."
 
-#: pkg/login.go:70 pkg/profile.go:90 pkg/contacts.go:264
+#: pkg/login.go:70 pkg/profile.go:90 pkg/contacts.go:270
 msgid "This value is not a valid email. It should be like name@domain.com."
 msgstr "Este valor no es un correo-e válido. Tiene que ser parecido a nombre@dominio.es."
 
@@ -254,43 +254,39 @@ msgstr "No podéis dejar la contraseña en blanco."
 msgid "Invalid user or password."
 msgstr "Nombre de usuario o contraseña inválido."
 
-#: pkg/products.go:39
-msgid "Select a tax for this product."
-msgstr "Escoged un impuesto para este producto."
-
-#: pkg/products.go:148
+#: pkg/products.go:193
 msgctxt "input"
 msgid "Name"
 msgstr "Nombre"
 
-#: pkg/products.go:154
+#: pkg/products.go:199
 msgctxt "input"
 msgid "Description"
 msgstr "Descripción"
 
-#: pkg/products.go:159
+#: pkg/products.go:204
 msgctxt "input"
 msgid "Price"
 msgstr "Precio"
 
-#: pkg/products.go:169 pkg/contacts.go:225
+#: pkg/products.go:214
 msgctxt "input"
-msgid "Tax"
-msgstr "Impuesto"
+msgid "Taxes"
+msgstr "Impuestos"
 
-#: pkg/products.go:189 pkg/profile.go:92
+#: pkg/products.go:234 pkg/profile.go:92
 msgid "Name can not be empty."
 msgstr "No podéis dejar el nombre en blanco."
 
-#: pkg/products.go:190
+#: pkg/products.go:235
 msgid "Price can not be empty."
 msgstr "No podéis dejar el precio en blanco."
 
-#: pkg/products.go:191
+#: pkg/products.go:236
 msgid "Price must be a number greater than zero."
 msgstr "El precio tiene que ser un número mayor a cero."
 
-#: pkg/products.go:193
+#: pkg/products.go:238
 msgid "Selected tax is not valid."
 msgstr "Habéis escogido un impuesto que no es válido."
 
@@ -398,57 +394,65 @@ msgctxt "input"
 msgid "Postal code"
 msgstr "Código postal"
 
-#: pkg/contacts.go:256
-msgid "Business name can not be empty."
-msgstr "No podéis dejar el nombre y los apellidos en blanco."
-
-#: pkg/contacts.go:257
-msgid "VAT number can not be empty."
-msgstr "No podéis dejar el DNI o NIF en blanco."
+#: pkg/contacts.go:225
+msgctxt "input"
+msgid "Country"
+msgstr "País"
 
 #: pkg/contacts.go:258
-msgid "This value is not a valid VAT number."
-msgstr "Este valor no es un DNI o NIF válido."
-
-#: pkg/contacts.go:260
-msgid "Phone can not be empty."
-msgstr "No podéis dejar el teléfono en blanco."
-
-#: pkg/contacts.go:261
-msgid "This value is not a valid phone number."
-msgstr "Este valor no es un teléfono válido."
-
-#: pkg/contacts.go:267
-msgid "This value is not a valid web address. It should be like https://domain.com/."
-msgstr "Este valor no es una dirección web válida. Tiene que ser parecida a https://dominio.es/."
-
-#: pkg/contacts.go:269
-msgid "Address can not be empty."
-msgstr "No podéis dejar la dirección en blanco."
-
-#: pkg/contacts.go:270
-msgid "City can not be empty."
-msgstr "No podéis dejar la población en blanco."
-
-#: pkg/contacts.go:271
-msgid "Province can not be empty."
-msgstr "No podéis dejar la provincia en blanco."
-
-#: pkg/contacts.go:272
-msgid "Postal code can not be empty."
-msgstr "No podéis dejar el código postal en blanco."
-
-#: pkg/contacts.go:273
-msgid "This value is not a valid postal code."
-msgstr "Este valor no es un código postal válido válido."
-
-#: pkg/contacts.go:275
 msgid "Selected country is not valid."
 msgstr "Habéis escogido un país que no es válido."
 
+#: pkg/contacts.go:262
+msgid "Business name can not be empty."
+msgstr "No podéis dejar el nombre y los apellidos en blanco."
+
+#: pkg/contacts.go:263
+msgid "VAT number can not be empty."
+msgstr "No podéis dejar el DNI o NIF en blanco."
+
+#: pkg/contacts.go:264
+msgid "This value is not a valid VAT number."
+msgstr "Este valor no es un DNI o NIF válido."
+
+#: pkg/contacts.go:266
+msgid "Phone can not be empty."
+msgstr "No podéis dejar el teléfono en blanco."
+
+#: pkg/contacts.go:267
+msgid "This value is not a valid phone number."
+msgstr "Este valor no es un teléfono válido."
+
+#: pkg/contacts.go:273
+msgid "This value is not a valid web address. It should be like https://domain.com/."
+msgstr "Este valor no es una dirección web válida. Tiene que ser parecida a https://dominio.es/."
+
+#: pkg/contacts.go:275
+msgid "Address can not be empty."
+msgstr "No podéis dejar la dirección en blanco."
+
+#: pkg/contacts.go:276
+msgid "City can not be empty."
+msgstr "No podéis dejar la población en blanco."
+
+#: pkg/contacts.go:277
+msgid "Province can not be empty."
+msgstr "No podéis dejar la provincia en blanco."
+
+#: pkg/contacts.go:278
+msgid "Postal code can not be empty."
+msgstr "No podéis dejar el código postal en blanco."
+
+#: pkg/contacts.go:279
+msgid "This value is not a valid postal code."
+msgstr "Este valor no es un código postal válido válido."
+
+#~ msgid "Select a tax for this product."
+#~ msgstr "Escoged un impuesto para este producto."
+
 #~ msgctxt "input"
-#~ msgid "Country"
-#~ msgstr "País"
+#~ msgid "Tax"
+#~ msgstr "Impuesto"
 
 #~ msgctxt "nav"
 #~ msgid "Customers"
diff --git a/revert/product_tax.sql b/revert/product_tax.sql
new file mode 100644
index 0000000..a78980e
--- /dev/null
+++ b/revert/product_tax.sql
@@ -0,0 +1,7 @@
+-- Revert numerus:product_tax from pg
+
+begin;
+
+drop table if exists numerus.product_tax;
+
+commit;
diff --git a/sqitch.plan b/sqitch.plan
index 4e21bb3..8746f04 100644
--- a/sqitch.plan
+++ b/sqitch.plan
@@ -45,3 +45,4 @@ to_price [schema_numerus] 2023-02-05T11:46:31Z jordi fita mas <jordi@tandem.blog
 invoice_status [schema_numerus] 2023-02-07T14:50:26Z jordi fita mas <jordi@tandem.blog> # A relation of invoice status
 invoice_status_i18n [schema_numerus invoice_status language] 2023-02-07T14:56:18Z jordi fita mas <jordi@tandem.blog> # Add relation for invoice status’ translatable texts
 available_invoice_status [schema_numerus invoice_status invoice_status_i18n] 2023-02-07T15:07:06Z jordi fita mas <jordi@tandem.blog> # Add the list of available invoice status
+product_tax [schema_numerus product tax] 2023-02-08T11:36:49Z jordi fita mas <jordi@tandem.blog> # Add relation of product taxes
diff --git a/test/product.sql b/test/product.sql
index af8dec8..b92abd6 100644
--- a/test/product.sql
+++ b/test/product.sql
@@ -5,7 +5,7 @@ reset client_min_messages;
 
 begin;
 
-select plan(55);
+select plan(49);
 
 set search_path to numerus, auth, public;
 
@@ -57,13 +57,6 @@ select col_type_is('product', 'price', 'integer');
 select col_not_null('product', 'price');
 select col_hasnt_default('product', 'price');
 
-select has_column('product', 'tax_id');
-select col_is_fk('product', 'tax_id');
-select fk_ok('product', 'tax_id', 'tax', 'tax_id');
-select col_type_is('product', 'tax_id', 'integer');
-select col_not_null('product', 'tax_id');
-select col_hasnt_default('product', 'tax_id');
-
 select has_column('product', 'created_at');
 select col_type_is('product', 'created_at', 'timestamp with time zone');
 select col_not_null('product', 'created_at');
@@ -73,7 +66,6 @@ select col_default_is('product', 'created_at', current_timestamp);
 
 set client_min_messages to warning;
 truncate product cascade;
-truncate tax cascade;
 truncate company_user cascade;
 truncate company cascade;
 truncate auth."user" cascade;
@@ -94,14 +86,9 @@ values (2, 1)
      , (4, 5)
 ;
 
-insert into tax (tax_id, company_id, name, rate)
-values (3, 2, 'IVA 21 %', 0.21)
-     , (6, 4, 'IVA 10 %', 0.10)
-;
-
-insert into product (company_id, name, description, price, tax_id)
-values (2, 'Product 1', 'Description 1', 1200, 3)
-     , (4, 'Product 2', 'Description 2', 2400, 6)
+insert into product (company_id, name, description, price)
+values (2, 'Product 1', 'Description 1', 1200)
+     , (4, 'Product 2', 'Description 2', 2400)
 ;
 
 prepare product_data as
diff --git a/test/product_tax.sql b/test/product_tax.sql
new file mode 100644
index 0000000..cd87c41
--- /dev/null
+++ b/test/product_tax.sql
@@ -0,0 +1,114 @@
+-- Test product_tax
+set client_min_messages to warning;
+create extension if not exists pgtap;
+reset client_min_messages;
+
+begin;
+
+select plan(23);
+
+set search_path to numerus, auth, public;
+
+select has_table('product_tax');
+select has_pk('product_tax' );
+select col_is_pk('product_tax', array['product_id', 'tax_id']);
+select table_privs_are('product_tax', 'guest', array []::text[]);
+select table_privs_are('product_tax', 'invoicer', array ['SELECT', 'INSERT', 'UPDATE', 'DELETE']);
+select table_privs_are('product_tax', 'admin', array ['SELECT', 'INSERT', 'UPDATE', 'DELETE']);
+select table_privs_are('product_tax', 'authenticator', array []::text[]);
+
+select has_column('product_tax', 'product_id');
+select col_is_fk('product_tax', 'product_id');
+select fk_ok('product_tax', 'product_id', 'product', 'product_id');
+select col_type_is('product_tax', 'product_id', 'integer');
+select col_not_null('product_tax', 'product_id');
+select col_hasnt_default('product_tax', 'product_id');
+
+select has_column('product_tax', 'tax_id');
+select col_is_fk('product_tax', 'tax_id');
+select fk_ok('product_tax', 'tax_id', 'tax', 'tax_id');
+select col_type_is('product_tax', 'tax_id', 'integer');
+select col_not_null('product_tax', 'tax_id');
+select col_hasnt_default('product_tax', 'tax_id');
+
+
+set client_min_messages to warning;
+truncate product cascade;
+truncate product_tax cascade;
+truncate tax cascade;
+truncate company_user cascade;
+truncate company cascade;
+truncate auth."user" cascade;
+reset client_min_messages;
+
+insert into auth."user" (user_id, email, name, password, role, cookie, cookie_expires_at)
+values (1, 'demo@tandem.blog', 'Demo', 'test', 'invoicer', '44facbb30d8a419dfd4bfbc44a4b5539d4970148dfc84bed0e', current_timestamp + interval '1 month')
+     , (5, 'admin@tandem.blog', 'Demo', 'test', 'admin', '12af4c88b528c2ad4222e3740496ecbc58e76e26f087657524', current_timestamp + interval '1 month')
+;
+
+insert into company (company_id, business_name, vatin, trade_name, phone, email, web, address, city, province, postal_code, country_code, currency_code)
+values (2, 'Company 2', 'XX123', '', '555-555-555', 'a@a', '', '', '', '', '', 'ES', 'EUR')
+     , (4, 'Company 4', 'XX234', '', '666-666-666', 'b@b', '', '', '', '', '', 'FR', 'USD')
+;
+
+insert into company_user (company_id, user_id)
+values (2, 1)
+     , (4, 5)
+;
+
+insert into tax (tax_id, company_id, name, rate)
+values (3, 2, 'IVA 21 %', 0.21)
+     , (6, 4, 'IVA 10 %', 0.10)
+;
+
+insert into product (product_id, company_id, name, description, price)
+values (7, 2, 'Product 1', 'Description 1', 1200)
+     , (8, 4, 'Product 2', 'Description 2', 2400)
+;
+
+insert into product_tax (product_id, tax_id)
+values (7, 3)
+     , (8, 6)
+;
+
+prepare product_tax_data as
+select product_id, tax_id
+from product_tax
+order by product_id, tax_id;
+
+set role invoicer;
+select is_empty('product_tax_data', 'Should show no data when cookie is not set yet');
+reset role;
+
+select set_cookie('44facbb30d8a419dfd4bfbc44a4b5539d4970148dfc84bed0e/demo@tandem.blog');
+select bag_eq(
+	'product_tax_data',
+	$$ values (7, 3)
+	$$,
+	'Should only list tax of products of the companies where demo@tandem.blog is user of'
+);
+reset role;
+
+select set_cookie('12af4c88b528c2ad4222e3740496ecbc58e76e26f087657524/admin@tandem.blog');
+select bag_eq(
+	'product_tax_data',
+	$$ values (8, 6)
+	$$,
+	'Should only list tax of products of the companies where admin@tandem.blog is user of'
+);
+reset role;
+
+select set_cookie('not-a-cookie');
+select throws_ok(
+	'product_tax_data',
+	'42501', 'permission denied for table product_tax',
+	'Should not allow select to guest users'
+);
+reset role;
+
+
+select *
+from finish();
+
+rollback;
+
diff --git a/verify/product.sql b/verify/product.sql
index ec643bf..a791537 100644
--- a/verify/product.sql
+++ b/verify/product.sql
@@ -8,7 +8,6 @@ select product_id
      , name
      , description
      , price
-     , tax_id
      , created_at
 from numerus.product
 where false;
diff --git a/verify/product_tax.sql b/verify/product_tax.sql
new file mode 100644
index 0000000..9c4519b
--- /dev/null
+++ b/verify/product_tax.sql
@@ -0,0 +1,13 @@
+-- Verify numerus:product_tax on pg
+
+begin;
+
+select product_id
+     , tax_id
+from numerus.product_tax
+where false;
+
+select 1 / count(*) from pg_class where oid = 'numerus.product_tax'::regclass and relrowsecurity;
+select 1 / count(*) from pg_policy where polname = 'company_policy' and polrelid = 'numerus.product_tax'::regclass;
+
+rollback;
diff --git a/web/template/form.gohtml b/web/template/form.gohtml
index 476afe6..f12f30c 100644
--- a/web/template/form.gohtml
+++ b/web/template/form.gohtml
@@ -1,10 +1,10 @@
 {{ define "input-field" -}}
     <div class="input {{ if .Errors }}has-errors{{ end }}">
         {{ if eq .Type "textarea" }}
-           <textarea name="{{ .Name }}" id="{{ .Name }}-field"
+            <textarea name="{{ .Name }}" id="{{ .Name }}-field"
                     {{- range $attribute := .Attributes }} {{$attribute}} {{ end }}
-                   {{ if .Required }}required="required"{{ end }} placeholder="{{ .Label }}"
-           >{{ .Val }}</textarea>
+                    {{ if .Required }}required="required"{{ end }} placeholder="{{ .Label }}"
+            >{{ .Val }}</textarea>
         {{ else }}
             <input type="{{ .Type }}" name="{{ .Name }}" id="{{ .Name }}-field"
                     {{- range $attribute := .Attributes }} {{$attribute}} {{ end }}
@@ -25,6 +25,7 @@
     <div class="input {{ if .Errors }}has-errors{{ end }}">
         <select id="{{ .Name }}-field" name="{{ .Name }}"
                 {{- range $attribute := .Attributes }} {{$attribute}} {{ end -}}
+                {{ if .Multiple }}multiple="multiple"{{ end }}
                 {{ if .Required }}required="required"{{ end }}
         >
             {{- with .EmptyLabel }}
@@ -32,7 +33,7 @@
             {{- end}}
             {{- range $option := .Options }}
                 <option value="{{ .Value }}"
-                        {{- if eq .Value $.Selected }} selected="selected"{{ end }}>{{ .Label }}</option>
+                        {{- if $.IsSelected .Value }} selected="selected"{{ end }}>{{ .Label }}</option>
             {{- end }}
         </select>
         <label for="{{ .Name }}-field">{{ .Label }}</label>