Final answer:
Banks and financial institutions may require customers to verify their account information every few years or when there are significant changes to their account. This is done for security purposes and to prevent unauthorized access.
Step-by-step explanation:
Banks and financial institutions often have policies in place to verify customer account information on a regular basis for security purposes. In the case of existing accounts, the frequency of written notices sent by the bank or financial institution for verification of account information may vary. Typically, banks and financial institutions will require customers to verify their account information every few years or when there are significant changes to their account.
For example, if a customer changes their address or contact information, the bank may send a written notice to the customer to verify the new information. Additionally, if there are any suspicious activities or security breaches related to the customer's account, the bank may also send a written notice for verification.
It's important for customers to respond promptly to such notices and provide the requested information to ensure the security of their account and prevent any unauthorized access or fraudulent activities.