If the system is not accepting your IBAN, then it may be coming from an unsupported bank. For Shopify Payments, you would need to connect a standard checking account opened with a European bank. Other types of bank accounts (e.g., savings) or those with a virtual bank account provider (e.g., e-wallet or cross-border services) are not supported. You will also need to ensure that your IBAN has the "IT" prefix.
If you're using a supported bank account, and the IBAN has an IT prefix, but are still getting the error, then please share a screenshot of the error you see as I can take a look.
Can you confirm whether the bank account you're trying to add falls within the criteria list above?
Thank you for letting me know! I have shipped you an email to verify the account so I can escalate the issue over to our Billing team.
Could you review the steps below and let me know what you find out?
If the above does not work, then I will reach you to gather a screenshot of the error, and a bank-issued document listing your IBAN so I can escalate this up to our Payments team for further review.