# Bank account number generation rules and authenticity identification ## General rules for generating bank account numbers The generation of bank account numbers usually follows specific rules, which vary from country to country and bank to bank.： 1. **Length specification**: The length of bank account numbers in different countries is different. Bank cards in mainland China are usually 16-19 digits, the United States is 9-12 digits, and European countries use the longer IBAN format. 2. **Components**： -Bank identification code (the first few digits) -Branch code (middle part) -Personal account number (middle part) -Check code (usually the last 1-2 digits) 3. **Check algorithm**: Most banks use Luhn algorithm or MOD 10 algorithm to generate check digits ##Method of identifying authenticity 1. **Check digit verification**: Use the Luhn algorithm to verify the last check digit 2. **BIN code query**: The first 6 digits are the identity of the issuing bank, you can check to confirm whether it matches the corresponding bank 3. **Format check**: Confirm whether the length and number composition comply with the bank's specifications 4. **Formal channel verification**: Account verification through the official bank channel It should be noted: I do not provide detailed generation rules or sample account numbers for specific banks to prevent them from being used for fraudulent activities. Legal verification of the authenticity of the account number should be carried out through the official bank channels.