Debt Repayment: Avalanche vs Snowball

If you have several debts, the order you repay them in changes both the total cost and the odds of finishing. There are two established approaches, and the argument between them is really a disagreement about whether people are calculators or human beings.

This is general information, not personal financial advice. If you are struggling to meet minimum payments, skip to the last section.

The setup, whichever method you choose

First, list every debt: who it is owed to, the balance, the interest rate, and the minimum payment. Credit cards, overdrafts, loans, car finance, buy-now-pay-later, catalogue accounts, money owed to family.

Then:

• Pay at least the minimum on everything, always. Missing minimums triggers fees and damages your credit file, which costs more than any strategy saves.
• Work out what you can put towards debt above the minimums. That surplus is your weapon.
• Direct the entire surplus at one debt at a time. Spreading it thinly across all of them achieves very little.

The only question is which debt gets the surplus.

The avalanche method

Target the debt with the highest interest rate first, regardless of size. When it clears, roll everything you were paying into the next highest rate.

Why it wins: interest is what makes debt expensive, so attacking the most expensive debt costs least overall and clears everything soonest. Mathematically, it is always at least as good as any alternative.

Why people abandon it: the highest-rate debt is often the largest. You can pay for months and still have the same number of debts, with nothing visibly finished. That is where motivation dies.

The snowball method

Target the smallest balance first, regardless of rate. Clear it, then roll that payment into the next smallest.

Why it works: you finish something quickly. Debts disappear from the list, the number of payments shrinks, and each win funds the next. Research into repayment behaviour has repeatedly found that people who see early progress are more likely to keep going.

Why it costs more: you may be clearing a small cheap debt while an expensive one keeps growing. The extra cost is real, though on typical household debts it is often smaller than people assume.

Which to choose

Be honest about yourself rather than idealistic.

• If you are motivated by numbers and have stuck to long financial plans before, use avalanche. It costs least.
• If you have started and abandoned repayment plans before, use snowball. A slightly more expensive plan you complete beats a cheaper one you quit.
• If the rates are all similar, use snowball — there is little to lose.
• If one debt has a punishing rate, deal with that one first whatever else you do.

A reasonable hybrid: clear one or two very small debts quickly for the momentum, then switch to strict avalanche.

Cut the interest rate itself

Before grinding through repayment, check whether the debt can be made cheaper:

• 0% balance transfer cards move credit card debt to an interest-free period for a one-off fee. Every payment then reduces the balance rather than the interest.
• Money transfer cards can clear an expensive overdraft.
• Asking your existing lender for a lower rate sometimes works, particularly if you have a good record.
• Consolidation loans can help, but only if the rate is genuinely lower and you do not re-spend on the cleared cards. Done badly, consolidation turns short-term debt into long-term debt and costs more.

Use eligibility checkers before applying, so you do not collect hard searches.

Guard against re-spending

The common failure is clearing a card and then using it again. When a card is cleared, either close it or remove it from your wallet and from stored payment details. Reduce the overdraft limit as you repay it.

Keep a small buffer

Putting every spare pound at debt with no savings at all usually backfires: the next unexpected cost goes straight back onto a card. A small emergency fund alongside repayment is not inefficiency, it is what stops the cycle restarting.

If the minimums are unaffordable

If you cannot meet minimum payments, or you are borrowing to repay borrowing, neither method applies and you need proper advice rather than a strategy.

Free, impartial help is available from StepChange, National Debtline, Citizens Advice and MoneyHelper. They can negotiate with creditors, arrange reduced payments, freeze interest, and explain formal options.

Never pay a company for debt help. Everything a fee-charging firm offers is available free, and paying for it makes a bad position worse.