Accountants do not have access to clients’ bank account so clients should be able to add their own bank accounts directly. However, this access must be limited to prevent clients from carrying out any further bank-related actions.

In particular, clients should not be able to match bank transactions to invoices, costs, or perform any reconciliation activities, as this remains the responsibility of the accountant.

So, could you consider one of the following options, please:
Updating the standard user role to allow clients to add bank accounts only, without granting any additional bank-related permissions; or
Creating a new user type with restricted permissions specifically for managing bank account details.