Many people think that the following figure 1 means they have received black money, but that is not the case. This is just the bank's normal risk control. If you have a card that you haven't used much, and suddenly receive a card that frequently transacts with others due to various reasons, you may be subject to risk control. If your card has a monthly turnover of several hundred thousand, entering a few thousand will not trigger the bank's risk control. In such cases, you should go to the bank, and they will ask you to provide the source of funds, such as salary statements. If what you provide meets their requirements, they will unfreeze it. However, it can be troublesome; it might be easier to just withdraw cash directly at the counter and cancel the card! For example, if your Alipay is frozen, it is not black money. Real black money is frozen directly by the police, and there will be a notice indicating which police station froze it. In fact, black money is quite rare. U merchants are more worried about black money than you are. You can feel how strict the checks are when you buy coins. When I withdraw money, I use a bank card, and every transaction is 100,000, and it won't get frozen! (Figure 2 is that case) Many people ask how to withdraw money if there are really several million. Some say to withdraw small amounts slowly, but in fact, withdrawing small amounts slowly carries more risk. Those who really have several million usually have large bank cards, like (Figure 3). Their usual turnover is also significant, generally still withdrawing using bank cards with tens of thousands. Saying something about U cards is just nonsense; once you convert to a U card, you cannot use it in mainland China!