01Which Method Should You Use? (Decision Matrix)
The honest verdict: the avalanche method (highest APR first) saves the most interest, but for a typical UK debt mix it is usually only a little, often a few pounds a month. The snowball method (smallest balance first) clears whole debts sooner, and that momentum is what gets people to the finish. Avalanche wins on paper. Snowball wins in real life.
Don't scroll. Pick your method now using this if/then logic:
| If You Are... | Choose | Why |
|---|---|---|
| Need a win in < 30 days | Snowball | First debt gone fast = motivation |
| Have 25%+ APR cards | Avalanche | Kill high interest first = save £££ |
| Math brain, patient | Avalanche | Optimal path, slower psychological wins |
| Tried before, quit | Snowball | Quick wins keep you going |
| Several debts < £1,000 | Snowball | Knock them out fast |
Pro Tip: See both methods side-by-side with your actual numbers. Takes 30 seconds.
02The Quick-Start: Snowball Method
Choose Snowball if you need a win in < 30 days.
You're not a robot. You need to feel progress. Snowball delivers that.
How it works: Attack your smallest debt first, regardless of interest rate. Pay minimums on everything else. When the smallest is gone, roll that payment into the next smallest.
Why it works: According to FCA research on behavioral economics, people in debt experience cognitive impairment. Complicated optimization fails. Simple momentum wins.
Example: £12k total, £400/month. Snowball clears your first debt in 8 months. That's your dopamine hit. That's what keeps you going for the next 26 months.
Snowball isn't about optimal maths. It's about not quitting. The best plan is the one you actually finish.
Ready? See your Snowball timeline with your actual debts in 60 seconds.
03The Optimizer: Avalanche Method
Choose Avalanche if you have high-interest cards (25%+) and a "maths brain."
You don't need quick wins. You need maximum savings. Avalanche delivers that.
How it works: Attack your highest APR debt first. Pay minimums on everything else. When the highest-rate debt is gone, move to the next highest.
Why it works: Interest is the enemy. A £5,000 debt at 29.9% APR costs you £1,495/year in interest alone. Kill it first, save the most.
Example: Same £12k total, £400/month. Avalanche saves you £150 in interest vs Snowball. Gets you debt-free 1 month faster. But your first debt takes 14 months to clear instead of 8.
Avalanche is optimal maths. But if you quit before month 14 because you see no progress? You save £0. Pick the method you'll finish.
Analytical type? See your Avalanche savings calculated to the penny.
04Yuki's Pro Tip: Custom Order (Pro)
You're not locked into one method. On Pro you can set a custom order and choose the exact sequence your debts get paid off in.
That's how you get the best of both. Clear your smallest debt first for the quick win, then reorder to put your highest-APR debt next so you stop bleeding interest. Snowball's momentum, avalanche's saving, in an order you control.
Snowball gets you started. Avalanche saves the most. Custom order lets you do both, in the sequence that actually fits your life. See your debt-free date, then try a different order.
05If you can't cover the minimums
A payoff method only works once you can meet your minimum payments each month. If you can't, a calculator is the wrong tool. Call StepChange on 0800 138 1111. Their debt advice is free, and they've seen your situation before.