0% balance transfer guide

How 0% Balance-Transfer Cards Work: Intro APR, Transfer Fees, and What Happens When the Promo Ends

A 0% intro APR card can stop interest from piling up while you pay down a balance. It works best with a payoff plan, because the fee is charged up front and the promotional rate ends.

By RateLever · Updated November 12, 2026 · About 9 min read

The basic idea

A balance transfer moves debt from one or more credit cards to a different card, usually a new one with a low or 0% introductory APR on transferred balances. For the length of that intro period, your payments go to principal instead of interest. When it ends, any balance left starts accruing interest at the card's regular APR.

Two numbers decide whether a transfer saves money: the transfer fee you pay up front and the interest you avoid during the intro period.

Transfer fees

Most balance-transfer cards charge a fee, often 3% to 5% of the amount moved. It's usually added to your new balance on day one. On a $6,800 transfer, a 3% fee is $204, so you start the new card owing $7,004.

A handful of cards advertise no transfer fee, often with a shorter intro period. Read the card's pricing table (sometimes called the Schumer box) for the exact fee, intro APR, intro length, and the APR that applies after.

A worked example

Say you owe $6,800 at 24.5% APR and move it to a card with 0% for 18 months and a 3% fee.

• To clear $7,004 in 18 months, you'd pay about $389 a month.
• Paying the same $389 a month on the original card would take about 22 months and cost about $1,697 in interest.
• So the transfer saves roughly $1,697 − $204 = about $1,490, if you stick to the plan.

Now say you can only pay $250 a month. After 18 months you'd still owe about $2,504, and that balance would start accruing interest at the card's regular rate. At 24.5%, that's about $51 of interest in the first month. You'd still likely come out ahead of staying put, but by less, and the remaining balance needs its own plan.

These numbers are illustrations. Your card's actual fee, intro length, and regular APR will differ. You can run your own in the balance transfer calculator.

What happens when the promo ends

With a true 0% intro APR on balance transfers, interest isn't charged back to the start. Whatever's left simply starts accruing interest at the regular APR from that point on. That's different from deferred interest offers, common on store cards and some financing deals, where interest can be charged retroactively on the whole original amount if you don't pay it off in time. Read the terms to know which kind you have.

Common ways a transfer goes wrong

• Missing a payment. A late payment can bring a late fee, hurt your credit, and in some cases cost you the promotional rate. Set up autopay for at least the minimum.
• Using the card for new purchases. The 0% rate may apply only to transfers, so purchases could accrue interest right away. Keeping the transfer card for the payoff alone keeps things simple.
• Running up the old card again. A transfer moves debt. It doesn't remove it. If the old card fills back up, you'll have more debt than you started with.
• A lower credit limit than expected. The issuer decides your limit after approval, and the fee counts against it. You may only be able to move part of the balance.
• Missing the transfer window. Many cards give the intro rate only to transfers made within a set time after you open the account.
• Same-issuer transfers. Issuers generally don't let you transfer a balance between two of their own cards.

How it can affect your credit

Applying for a new card usually means a hard inquiry and a new account, which can lower a score a little for a while. Over time, paying the balance down lowers your credit utilization, the share of available credit you're using, which tends to help. Closing the old card can raise utilization and shorten your credit history, so think before closing it, though a card with an annual fee you don't want is a reasonable exception.

Is a balance transfer right for you?

It tends to work best when you have steady income, can pay off most or all of the balance within the intro period, and qualify for a card with a long enough promo. If you can't qualify, or the payoff would take years, a fixed-rate personal loan or a nonprofit credit counseling agency may be worth comparing. Our guide to personal loans vs. balance transfers walks through the tradeoffs.

For official background, see the CFPB's explainer on balance transfer fees on 0% offers and its credit card resources.