Yes, legally the electronic invoice must include the recipient's DIR3 code . However, in practice, we do not tend to manage invoices by DIR3 code but by NIF, and not all of us have yet identified their accounting offices with their corresponding DIR3 code. However, work is being done so that all of us have their DIR3 codes defined and can comply with the standard. It is for this reason that in the near future it will be mandatory to report this information on invoices.
The Catalan Public Administrations can always reject invoices if they require the DIR3 codes and they are not well informed. However, e-FACT currently does not validate DIR3 codes, nor does it reject invoices if the DIR3 codes are not correctly reported.