Imports historical bank transactions for this account from the provider over a date range, then runs matching against the account's full current card set. Unlike the backfill object on PATCH /bank-accounts/{bankAccountId} — which imports history for cards being added in that same request — this endpoint recovers a date window without touching card links.

Requires a backing connection. Starting a backfill while another sync already holds the account's connection returns 409 Conflict; retry shortly.

For Mastercard-provider accounts, loadHistoric: true additionally asks the provider to generate deep history (up to 2 years) for this account before the import runs. This is a billable provider operation and generation is asynchronous on the provider side: if the immediate import returns few rows, re-run the same window without the flag once generation completes (typically within minutes). Providers without a deep-history operation reject the flag with 400 Bad Request.