/// <summary> /// Calculates IBAN's check digit. /// ISO13616 /// </summary> /// <param name="iban">IBAN object</param> /// <returns>Check digit as string</returns> /// <exception cref="IbanFormatException">Thrown if supplied iban string contains invalid chracters</exception> public static string CalculateCheckDigit(Iban iban) => CalculateCheckDigit(iban.ToString());