How do I know which characters are acceptable in Bacs files? Cloud Payments Expert July 04, 2018 14:44 Updated Follow The below list of the special Characters are allowed by Bacs: Uppercase Alpha A to Z Numeric 0 to 9 Space Hyphen - Full Stop (decimal) . Ampersand & Solidus / ISO 20022/Bacs Related articles How do I find more UK Sort Code & Account Number Validation test cases? How should my file be formatted? How do I manually install the Gemalto Certificates? What are Bacs reports? How do I reject/discard payment files in PTX?