Businesses that accept checks often use some form of bank account verification. Bank account verification is used for other reasons as well, including when people apply for loans, credit accounts, and credit cards.
Merchants that offer in-house credit accounts to their customers often use bank account verification. This protects the merchant by ensuring an applicant's bank account is in good standing. It also ensures the customer has a bank account that is open. The merchant requests the applicant's bank account number and routing number to accomplish this procedure.
Businesses that accept checks often run the check through a system for bank account verification. This system is an expense for businesses; however, it protects businesses from collecting checks from customers whose account has insufficient funds. The merchant gets an instant approval or denial from the system.
When people apply for credit cards, some banks will request a bank account verification. The financial institution issuing the card does this to protect itself. The bank ensures the applicant has an open account that is in good standing.