The Debt Avalanche Method: Step-by-Step Guide for UK Borrowers
The debt avalanche is the most mathematically efficient way to pay off multiple debts. You pay the minimum on everything, then throw any extra money at the debt with the highest APR. Once that's gone, you roll the payment to the next highest, and so on. In the UK, where credit card rates are often 20–25%+, targeting the most expensive debt first can save thousands of pounds and years of payments.
How the debt avalanche method works
The core principle is simple: interest is your enemy. Every month a high-APR debt sits unpaid, it generates more interest than a lower-rate debt of the same size. By eliminating your highest-rate debts first, you slow the growth of your overall debt pile and shrink the total interest you pay over time.
The "avalanche" name comes from the idea that once you clear one debt, that full monthly payment — minimum plus extra — crashes into the next one, accelerating the payoff. Each debt you clear makes the next one faster to eliminate.
Five steps to set it up
List all your debts with their APR
Write down every credit card, store card, overdraft, and personal loan — the balance, the APR, and the minimum payment for each. Your statement or online banking will show all three. If an overdraft has a daily fee rather than an APR, convert it: a 39.9% EAR overdraft is roughly 39.9% APR.
Sort by APR, highest first
Rank your debts from the highest interest rate to the lowest. This becomes your attack order. The top of the list is your avalanche target — everything else just gets the minimum.
Set up minimum payments on all debts
Use direct debits so you never miss a payment. Missing a minimum on any debt triggers late fees and can damage your credit file — which could cost you more than the debt itself in the long run.
Put every extra pound at the top-APR debt
Work out how much you can realistically pay each month above the total of all your minimums — even £30–50 makes a meaningful difference. Put that entire extra amount at your highest-APR debt. Don't split it across debts; concentrated firepower is the whole point of the method.
Roll the payment when a debt clears
When your top-APR debt reaches zero, don't reduce your monthly outgoing. Take the full amount you were paying on it — minimum plus extra — and add it to the minimum of the next debt on your list. The payments compound as you go, and the avalanche speeds up.
Worked example: three UK debts
Suppose you have these three debts and can afford £50 extra per month on top of all your minimums:
| Debt | Balance | APR | Min payment | Avalanche order |
|---|---|---|---|---|
| Store card | £800 | 34.9% | £25 | ① Attack first |
| Credit card | £2,400 | 22.9% | £55 | ② Next |
| Personal loan | £4,500 | 9.9% | £110 | ③ Last |
Your total minimum commitment is £190/month. You pay that on all three, plus your £50 extra goes entirely to the store card (highest APR). Once the store card is cleared — roughly 10–11 months — you redirect its full £75 (old minimum £25 + extra £50) on top of the credit card's £55 minimum. Now you're putting £125+ at the credit card while still paying the minimum on the loan. The loan's low 9.9% APR means interest grows slowly while you clear the expensive debts first.
How does it compare to the snowball?
With the snowball method you'd attack the store card first anyway (it's the smallest balance too), but the credit card next — and you'd pay the personal loan last, same as here. In this particular example the two methods happen to produce similar results because the highest-APR debt is also the smallest balance.
But change the balances slightly — say the credit card is the smallest — and the snowball would have you paying that off first while the 34.9% store card keeps accumulating interest. Over a year that extra compounding costs real money. To see the difference for your specific debts, put your real numbers into the free calculator and compare both methods side by side.
When the avalanche works best
- You have at least two debts with meaningfully different APRs — the bigger the gap, the bigger the saving.
- You can commit to a consistent monthly payment for the duration. The avalanche relies on discipline; if you dip into savings or reduce payments irregularly, the numbers shift.
- Your highest-APR debt isn't so large that it takes years to clear before you feel any progress. If motivation is a concern, the snowball's early wins may keep you on track better. See the snowball guide for an honest comparison.
Combining with a 0% balance transfer
The avalanche is about attacking the highest APR first. The logical extension: if you can transfer a high-rate balance to a 0% balance transfer card, you've temporarily eliminated that debt's APR — meaning every pound you pay reduces the balance directly, with no interest leakage. This can dramatically accelerate the payoff. We cover the full combined strategy in 0% Balance Transfer + Debt Avalanche: The Fastest Way Out of Credit Card Debt.
Key takeaways
- Pay minimums on all debts; put every extra pound at the highest APR debt.
- When a debt clears, roll the full payment onto the next highest-APR debt.
- In the UK, where card APRs are often 20–25%+, this method typically saves the most money.
- The bigger the gap between your highest and lowest APRs, the bigger the saving over the snowball.
- Use the free calculator to see your exact debt-free date and total interest for avalanche vs snowball with your own numbers.