An accidental overdraft like that shouldn't derail your approval. An overdraft doesn't automatically flag in the automated underwriting system, and it isn't a hard stop. What likely happened is simple sequencing: money left one account to pay the card before the offsetting deposit or transfer landed, and the balance dipped negative for a moment. Worst case, an underwriter reviewing your bank statements notices it and asks for a short written explanation. That's easy to provide, because the truth is exactly what happened: a timing gap in funds moving between accounts, with the money there to cover it. A one-line letter of explanation usually puts it to rest. A few habits keep you out of that conversation entirely: - Keep a small cushion in the account you pay bills from. - Avoid timing large debt paydowns right against other outflows in the weeks before and during underwriting. - Steer clear of large unexplained deposits while you're in the loan, since underwriters review your most recent statements. - If something odd does appear, tell your loan team proactively. A heads-up with the explanation attached is always smoother than a surprise mid-underwriting.