Balance Transfer Math: When 0% APR Is a Trap

Some calculations matter for a single decision; this one matters for years. 0% APR balance-transfer offers feel like free money. Run the numbers before you accept.

The transfer fee

Usually 3–5% upfront. Transfer $10,000 = $300–500 cost on day one.

The promo window

12–21 months. Whatever you do not clear by then drops to standard APR (often 20%+).

The break-even

If your current card's APR is 18%+ and you can clear it during the promo, transfer is a clear win. Otherwise, math it out.

Pro tips

• Cut up the old card — or at least freeze it — to avoid rebuilding the balance you just moved.
• Set a calendar reminder for 30 days before promo ends.

Frequently asked questions

Does the transfer hurt my credit? Short term yes (hard inquiry, new account), long term often helps (lower utilisation).

Can I transfer between cards at the same bank? Usually not — most issuers forbid same-bank transfers.

Whatever number you land on, sanity-check it against a second method or a quick estimate in your head.