Wallet linking is the one-time setup that joins a digital wallet to another account so that money can move between them without re-entering details. The term covers two directions. In the first, the user links a bank account or card to the wallet as a wallet funding source, which is then used for a wallet top-up, for payments drawn through the wallet and for withdrawals. In the second, the user links the wallet to a merchant, ride-hailing or shopping app, giving that app permission to charge the wallet for future purchases.
In both cases the provider must confirm that the person linking controls the account being linked. Bank accounts are verified by logging in through the bank, by micro-deposit verification or by a one-time code, and cards by an authentication challenge. Merchant links are usually granted through a redirect to the wallet app, where the user approves and a token is issued to the merchant.