What Happens to a Balance Transfer's Interest Rate After the Promo Ends?
Moving a balance to a card with a low promotional rate can feel like solving the interest problem entirely, but the promotional period is a window, not a permanent feature, and what happens when it closes deserves as much attention as the offer that opened it.
The short answer
Once a balance transfer’s promotional period ends, any remaining balance typically starts accruing interest at the card’s standard ongoing APR for balance transfers or purchases, whichever applies under the card’s terms. That standard rate is usually considerably higher than the promotional one, and it applies going forward from the expiration date rather than retroactively to the whole transferred amount.
Why the shift can feel sudden
During the promotional period, a transferred balance may accrue little or no interest, which can make the monthly statement feel deceptively simple. Once the period ends, the same balance is recalculated under the card’s regular ongoing rate, and because interest is generally calculated on a daily balance, the new charges start showing up almost immediately on the next statement. The size of the shift depends on how much of the balance is still outstanding when the promotional window closes — a balance paid down close to zero barely notices the change, while a balance largely untouched can see a substantial new interest charge appear.
What else was true from the start
A few details from the original transfer are worth remembering as the promotional period winds down:
- The transfer fee was separate from the rate. Many balance transfers carry an upfront fee calculated as a percentage of the amount moved, charged regardless of how the promotional rate performs, which is part of how a balance transfer generally works from the outset.
- New purchases may follow different terms. Depending on the offer, purchases made on the same card during the promotional period might accrue interest under separate terms from the transferred balance, so the expiration date for one doesn’t necessarily match the other.
- The standard rate was disclosed at the start. The rate that takes over after the promotion ends is typically stated in the account’s original terms, even though it may not have been the headline figure in the promotional offer.
Planning around the expiration date
Because the standard rate applies from the expiration date forward rather than retroactively, the practical question is simply how much balance remains at that point. Someone who divides the original balance by the number of promotional months, and pays that amount each cycle, generally reaches zero right as the standard rate would otherwise kick in — though actual results depend on individual payment patterns and any additional purchases made along the way.
What to weigh
The specific standard rate, how it compares to an ordinary APR, and whether it’s fixed or variable all depend on the individual card’s terms, so it’s worth checking the account agreement rather than assuming a particular number. Treating the promotional period as a fixed-length runway — with a known, if less favorable, rate waiting at the end of it — is a more accurate way to plan than assuming the low rate will simply continue.
A practical habit
Marking the exact expiration date of a balance transfer promotion, and checking the remaining balance against it periodically, turns an easy-to-miss deadline into a known point on the calendar rather than a surprise on a future statement.