Context

When sending funds to Bridge, we need to know how to match those funds to a transfer to process the transaction. For developers who use Virtual Accounts, there is no memo required since the Virtual Account provides the deposit instructions. However, other transactions require a memo to be processed. This can be a static memo or a unique memo that is provided when the transfer is created.

Answer

If Bridge receives funds without a memo (when required), these funds with be unmatched. Bridge reaches out to developers to provide information on these unmatched funds. When Bridge receives the correct memo, the deposit can be matched and the transferred processed. If the memo is not provided, Bridge will automatically return the funds after 2 business days for wire and SEPA deposits and 5 business days for ACH deposits.

More information is available here.