An Invalid IBAN error means the IBAN has failed validation.
Please check that:
(1) the IBAN has no spaces or special characters
(2) the country code matches the bank's country
(3) the length matches the country's IBAN standard (e.g., 22 characters for Maltese IBANs)
(4) all digits/letters are entered correctly. Re-confirm the IBAN with your beneficiary before retrying