diff --git a/pkg/form.go b/pkg/form.go
index 8adcede..fe41570 100644
--- a/pkg/form.go
+++ b/pkg/form.go
@@ -66,6 +66,7 @@ func (field *InputField) Float64() float64 {
 type SelectOption struct {
 	Value string
 	Label string
+	Group string
 }
 
 type SelectField struct {
@@ -158,6 +159,29 @@ func MustGetOptions(ctx context.Context, conn *Conn, sql string, args ...interfa
 	return options
 }
 
+func MustGetGroupedOptions(ctx context.Context, conn *Conn, sql string, args ...interface{}) []*SelectOption {
+	rows, err := conn.Query(ctx, sql, args...)
+	if err != nil {
+		panic(err)
+	}
+	defer rows.Close()
+
+	var options []*SelectOption
+	for rows.Next() {
+		option := &SelectOption{}
+		err = rows.Scan(&option.Value, &option.Label, &option.Group)
+		if err != nil {
+			panic(err)
+		}
+		options = append(options, option)
+	}
+	if rows.Err() != nil {
+		panic(rows.Err())
+	}
+
+	return options
+}
+
 func mustGetCountryOptions(ctx context.Context, conn *Conn, locale *Locale) []*SelectOption {
 	return MustGetOptions(ctx, conn, "select country.country_code, coalesce(i18n.name, country.name) as l10n_name from country left join country_i18n as i18n on country.country_code = i18n.country_code and i18n.lang_tag = $1 order by l10n_name", locale.Language)
 }
diff --git a/pkg/invoices.go b/pkg/invoices.go
index 0a2e9cc..6f2d6a3 100644
--- a/pkg/invoices.go
+++ b/pkg/invoices.go
@@ -418,7 +418,7 @@ func (form *invoiceForm) AddProducts(ctx context.Context, conn *Conn, productsId
 }
 
 func mustGetTaxOptions(ctx context.Context, conn *Conn, company *Company) []*SelectOption {
-	return MustGetOptions(ctx, conn, "select tax_id::text, name from tax where company_id = $1 order by name", company.Id)
+	return MustGetGroupedOptions(ctx, conn, "select tax_id::text, tax.name, tax_class.name from tax join tax_class using (tax_class_id) where tax.company_id = $1 order by tax_class.name, tax.name", company.Id)
 }
 
 type invoiceProductForm struct {
diff --git a/web/template/form.gohtml b/web/template/form.gohtml
index 486b012..6b9eadb 100644
--- a/web/template/form.gohtml
+++ b/web/template/form.gohtml
@@ -43,15 +43,26 @@
     <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 }}
+                {{ if .Multiple }} multiple="multiple"{{ end -}}
+                {{ if .Required }} required="required"{{ end -}}
         >
             {{- with .EmptyLabel }}
                 <option value="">{{ . }}</option>
             {{- end}}
+            {{- $withinGroup := "" -}}
             {{- range $option := .Options }}
+        {{- if ne .Group $withinGroup }}
+        {{- if ne $withinGroup "" }}
+            </optgroup>
+        {{ end }}
+            <optgroup label="{{ .Group }}">
+                {{- $withinGroup = .Group -}}
+                {{ end }}
                 <option value="{{ .Value }}"
                         {{- if $.IsSelected .Value }} selected="selected"{{ end }}>{{ .Label }}</option>
+                {{- end }}
+                {{- if ne $withinGroup "" }}
+            </optgroup>
             {{- end }}
         </select>
         <label for="{{ .Name }}-field">{{ .Label }}</label>