fix: Allow mixed digit and letter in two first chars of FR VAT nb

rates_test.go

@@ -17,8 +17,8 @@ func TestCountryRates_GetRate(t *testing.T) {
 	}
 
 	c, _ = GetCountryRates("RO")
-	if r, _ := c.GetRate("standard"); r != 19 {
-		t.Errorf("Standard VAT rate for RO is supposed to be 19. Got %.2f", r)
+	if r, _ := c.GetRate("standard"); r != 21 {
+		t.Errorf("Standard VAT rate for RO is supposed to be 21. Got %.2f", r)
 	}
 }
 

validate.go

@@ -33,7 +33,7 @@ func ValidateFormat(vatNumber string) error {
 		"EL": `[0-9]{9}`,
 		"ES": `[A-Z][0-9]{7}[A-Z]|[0-9]{8}[A-Z]|[A-Z][0-9]{8}`,
 		"FI": `[0-9]{8}`,
-		"FR": `([A-Z]{2}|[0-9]{2})[0-9]{9}`,
+		"FR": `[A-Z0-9]{2}[0-9]{9}`,
 		// Supposedly the regex for GB numbers is `[0-9]{9}|[0-9]{12}|(GD|HA)[0-9]{3}`,
 		// but our validator service only accepts numbers with 9 or 12 digits following the country code.
 		// Seems like the official site only accepts 9 digits... https://www.gov.uk/check-uk-vat-number

validate_test.go

@@ -49,6 +49,9 @@ var tests = []struct {
 	{"FI1234567", ErrInvalidVATNumberFormat},
 	{"FI12345678", nil},
 	{"FR12345678901", nil},
+	{"FR1B345678901", nil},
+	{"FRAB345678901", nil},
+	{"FRABC45678901", ErrInvalidVATNumberFormat},
 	{"FR1234567890", ErrInvalidVATNumberFormat},
 	{"GB999999973", nil},
 	{"GB156730098481", nil},