Id card, unit certificate, income certificate and tax payment certificate, pension insurance payment certificate. It doesn't necessarily depend on which bank has the lowest requirements. It depends on how many credit cards you want to apply for. The same income certificate of the same person, investing in different banks, the approved credit line is different. In contrast, the post office has the lowest requirements, but the post office cards can't be swiped in many places. It is not particularly convenient for many banks to install POS machines without reaching an agreement with the post office.