Interest-free periods: how they work and how they end

Resources · Debt basics · 5 min read Building

Key points

• An interest-free period is a set time when a balance attracts no interest.
• When it ends, a much higher standard rate usually applies to whatever is left.
• Some deals charge back the interest from day one if the balance isn’t fully cleared.
• Divide the balance by the number of months and you have the payment that clears it in time.

What an interest-free period is

An interest-free period is a stretch of time when you pay no interest on a balance. Sounds simple. The catch is in how it ends.

You’ll run into them in a few places. There are promotional purchase deals, like “no interest for 12 months” on furniture or electronics. There are balance transfer offers, where a debt moves to a card with a low or zero rate for a set time. A credit card also has a regular grace period: new purchases attract no interest if you pay the full statement balance by the due date. And buy now, pay later plans split a purchase into instalments.

The details vary a lot between products and countries. Your terms and conditions spell out exactly how yours works. Read them.

What happens when the interest-free period ends

Every interest-free period has an end date. After that, a standard rate kicks in, and it’s often high.

It can play out in two main ways. Your terms will say which one you’ve got.

1. Interest starts on what’s left

This is the common one. From the end date, interest is charged on the remaining balance at the standard rate. Whatever you paid off during the free period stays interest-free.

2. Interest is charged back to the start

Some deals, sometimes called deferred interest, are harsher. If you haven’t cleared the whole balance by the end date, interest gets added for the entire period, as if the deal had never been interest-free at all. That can be a big, sudden jump.

A worked example

Say you buy something for $2,400 on a 12-month interest-free deal. After the 12 months, a standard rate of 24% APR applies. Interest is charged monthly at 24% ÷ 12 = 2%, on the balance before each payment. The same maths works in any currency.

Paying $200 a month. $2,400 ÷ 12 = $200. After 12 payments, the balance is $0. No interest charged. Done.

Paying $150 a month. After 12 payments you’ve paid $1,800, so $600 is still there when the period ends. What it costs you now depends on the type of deal.

If interest starts on what’s left, the first month’s interest is $12.00. Keep paying $150 a month and the $600 clears in 5 more months, with $31.83 of interest in total.

If interest is charged back to the start, it’s worked out on the balance each month across the whole 12 months, before each payment. That comes to $378.00, added on top of the $600 you still owe.

Fifty dollars a month doesn’t look like much of a gap. Under a charge-back deal, the gap in cost is anything but small.

Things that can end it early

Some deals stop before the advertised date. A missed or late payment can cancel the promotional rate straight away on some terms. New spending on the same card can catch you out too, because on some cards new purchases attract interest even while a transferred balance doesn’t, and your payments may be applied in a set order. Then there’s the fee to get started. Some balance transfers charge a one-off fee that’s added to the balance, so check the terms.

Read the terms before the deal starts. Write the end date somewhere you’ll actually see it.

Planning for the end date

There’s no single way to do this, but a few habits make it much harder to get caught out:

• Divide and pay. Take the balance, divide it by the months in the deal, and pay that every month. Rounding up gives you a little breathing room.
• Set a reminder. A calendar note a couple of months before the end date gives you time to check where the balance sits.
• Track it on its own line. Put the promotional balance as a separate line in your debt list so the end date stays in view.

Some people use a balance transfer to pause interest while they pay a debt down. Others steer clear because of the fees and the risk of a higher rate afterwards. Both camps have a point. It comes down to whether the numbers work for you, and whether you can honestly clear the balance in time.

If you already know you won’t keep up with payments once a deal ends, free debt help is available, and it’s confidential.

Common questions

What happens at the end of an interest-free period?

A standard rate, often a high one, usually applies to whatever’s left. On deferred interest deals, interest can be charged back to the start if you haven’t fully cleared the balance.

How do I clear a balance before the interest-free period ends?

Divide the balance by the number of months in the deal and pay at least that each month. Round up if you can, for a bit of breathing room.

Can an interest-free period end early?

On some deals, yes. A missed or late payment can cancel the promotional rate. Your terms say what applies to you.

Try it

Use the credit card payoff calculator to see what any balance left at the end of a deal would cost at the standard rate. Then find your Freedom Date with everything you owe.

General information only, not financial advice. Your situation is your own.