Can I sue if I receive a fake lawyer's letter?

Legal analysis: you can file a case, and the lawyer's letter is the proof of the other party's reminder. If the loan is not repaid, the other party can sue you for repayment through legal means, but the interest supported by the court is four times the bank's loan interest rate for the same period. If it exceeds its standard, the law will not support it. Therefore, if the interest standard agreed by both parties exceeds this standard, it will not be protected by law. If the court decides that you don't perform compulsory execution and repay the loan, you will be placed on the list of dishonesty, restrict consumption, freeze bank cards, and even seal up auction houses and vehicles. However, it does not rule out that the other party uses improper means to urge the payment of arrears. The false lawyer's letter issued by the collection agency has no legal effect, and the parties concerned can ignore it after receiving the false lawyer's letter. If there is a dispute, you can also resort to the court.

Legal basis: Article 3 of the Civil Procedure Law of People's Republic of China (PRC). The provisions of this Law shall apply to the people's courts in accepting civil lawsuits brought by citizens, legal persons, other organizations and their property relations and personal relations.