You may not be found out for the time being, but if you are overdue or default in the future, the bank will verify the income certificate. If it is found that the official seal is fake, it will be legally responsible.

Criminal Law of the People's Republic of China and the People's Republic of China?

Article 280: Who forges, alters, trades, or steals, robs, or destroys official documents, certificates, and seals of state agencies , shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention, public surveillance or deprivation of political rights; if the circumstances are serious, he shall be sentenced to fixed-term imprisonment of not less than three years but not more than ten years. ?

Whoever forges the seal of a company, enterprise, institution, or people's organization shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention, public surveillance, or deprivation of political rights. ?

Whoever forges or alters a resident identity card shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention, public surveillance, or deprivation of political rights; if the circumstances are serious, he shall be sentenced to fixed-term imprisonment of not less than three years but not more than seven years.