Generally, the principal is 5,000 yuan, and if it is collected for more than 3 months, it may be criminally detained. If the amount owed reaches more than 1 10,000 yuan, and the card issuer fails to return it twice in more than 3 months, it should be considered as malicious overdraft in criminal law and suspected of credit card fraud. If the amount of malicious overdraft is large, and all overdraft interest has been repaid before the public security organ files a case, criminal responsibility may not be investigated according to law. Credit card fraud is suspected of one of the following circumstances: (1) using forged credit cards, or using credit cards fraudulently obtained with false identity documents, or using invalid credit cards, or fraudulently using other people's credit cards for fraudulent activities, with an amount of more than 5,000 yuan; (2) Malicious overdraft. 1. The amount is relatively large: more than 50,000 yuan and less than 500,000 yuan. 2. The amount is huge: more than 500,000 yuan and less than 5 million yuan. The amount is huge: more than 5 million yuan.