diff --git a/regimes/ch/invoices_test.go b/regimes/ch/invoices_test.go
new file mode 100644
index 00000000..7a13aebb
--- /dev/null
+++ b/regimes/ch/invoices_test.go
@@ -0,0 +1,60 @@
+package ch_test
+
+import (
+	"testing"
+
+	"github.com/invopop/gobl/bill"
+	"github.com/invopop/gobl/num"
+	"github.com/invopop/gobl/org"
+	"github.com/invopop/gobl/tax"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func validInvoice() *bill.Invoice {
+	return &bill.Invoice{
+		Series: "TEST",
+		Code:   "0002",
+		Supplier: &org.Party{
+			Name: "Test Supplier",
+			TaxID: &tax.Identity{
+				Country: "CH",
+				Code:    "E100416306",
+			},
+		},
+		Customer: &org.Party{
+			Name: "Test Customer",
+			TaxID: &tax.Identity{
+				Country: "CH",
+				Code:    "E432825998",
+			},
+		},
+		Lines: []*bill.Line{
+			{
+				Quantity: num.MakeAmount(1, 0),
+				Item: &org.Item{
+					Name:  "bogus",
+					Price: num.MakeAmount(10000, 2),
+					Unit:  org.UnitPackage,
+				},
+				Taxes: tax.Set{
+					{
+						Category: "VAT",
+						Rate:     "standard",
+					},
+				},
+			},
+		},
+	}
+}
+
+func TestInvoiceValidation(t *testing.T) {
+	inv := validInvoice()
+	require.NoError(t, inv.Calculate())
+	assert.NoError(t, inv.Validate())
+
+	inv = validInvoice()
+	inv.Supplier.TaxID.Code = ""
+	require.NoError(t, inv.Calculate())
+	assert.Error(t, inv.Validate())
+}