Is a 0% balance transfer worth the fee?

A 0% balance transfer is one of the few genuinely good deals available to someone carrying card debt. It is also sold with a fee attached and a deadline, and both of those get glossed over.

The arithmetic is simple enough to do in your head, so do it before you apply.

The break-even

Transfer fees are typically 3% to 5% of the amount moved, charged immediately and added to the transferred balance.

Move $8,000 from a card charging 24%:

• A 3% fee costs $240, added to the balance on day one.
• Interest you would have paid on $8,000 at 24% is roughly $160 a month at the start.

So the fee is paid back in about six weeks of avoided interest. Everything after that is yours. On those numbers the transfer is obviously worth it — and for most people carrying a real balance at a real rate, it is.

The transfer stops being worth it when the promotional window is short, the fee is 5%, and your existing rate is modest. A 5% fee to escape a 12% rate for twelve months is roughly break-even: you pay 5% up front to avoid about 12% for a year on a declining balance, which nets out to very little.

The balance transfer calculator puts the fee, the promotional window and the rate that takes over afterwards on one timeline, including what happens if you are still carrying a balance when the clock runs out.

The number that actually matters

Not the fee. The monthly payment that clears the whole balance inside the promotional window.

$8,000 plus a $240 fee is $8,240. Over an 18-month promotion that is about $458 a month. If you cannot commit to that, you will be holding a balance when the promotion ends, and it will be repriced at the go-to rate — which is often as high as the rate you left.

Work out that figure first. It tells you whether the offer is a solution or a postponement.

Two federal rules that are on your side

Most people transferring a balance do not know these, and both are worth knowing.

Payments above the minimum go to the most expensive balance first. Under Regulation Z, when you pay more than the required minimum on a credit card, the issuer must allocate the excess first to the balance with the highest annual percentage rate, then to the others in descending rate order. So if you have a 0% transferred balance and later make purchases at 22%, your extra payments attack the 22% first automatically. You do not have to ask.

A single late payment cannot end your promotional rate. The rule permits an issuer to raise a rate for delinquency only when the required minimum payment is more than 60 days overdue. One missed due date is bad — a late fee, and the risk to your credit file — but it does not by itself cost you the promotion. Separately, a promotional rate has to run for a stated period of six months or longer, disclosed in advance along with the rate that applies afterwards.

The rule that is not on your side

The grace period. On most cards, if you are carrying a balance, new purchases begin accruing interest immediately rather than getting the usual interest-free window until the due date.

So a card you have just filled with transferred debt is a bad card to spend on — and the transferred balance sitting there is exactly what removes the grace period. Move the balance, then put the card away and use a different one for day-to-day spending.

What to ask before applying

1. What is the fee, and is it capped? Some offers cap the fee in dollars, which changes the arithmetic on large balances.
2. How long is the 0% window, and does it start at account opening or at transfer? Transfers can take a couple of weeks, and on some cards the clock starts before the money moves.
3. What is the go-to rate? That is the rate on anything left at the end.
4. Does the 0% apply to purchases too, or only transfers?
5. Is there a transfer limit? Approved limits are frequently smaller than the balance you wanted to move.
6. What monthly payment clears it inside the window? If you cannot answer this one, the others do not matter much.

A transfer does not reduce what you owe. It stops the meter for a fixed period and charges you a fee for doing so. Used as a deadline to clear the balance, it is excellent. Used as a way to lower the monthly payment, it tends to arrive back where it started, minus the fee.

Sources: Regulation Z § 1026.53 on allocation of payments, and § 1026.55 on limitations on increasing annual percentage rates, including the temporary-rate and 60-day delinquency provisions.