The total length of the given sort code and bank account number, is not equal to 14 digits.

The PH Bank Account numbers consist of:

You can specify the receivers bank account number in only one way in the bank account form

Specify the receivers bank account number only by using the “Bank Account No.” field

1. Specify always your receivers bank account number as 14  digits following the above syntax.
2. You must always specify there sortcode number in the beginning of the field and it must be 6 digits (no chars only digits).

Do you need some help, you can always raise a support case here