Should I pay off debt or build savings first? (the actual answer)

If you’ve typed this question into Google, there’s a good chance you already know what the “correct” answer is supposed to be. Pay off the high-interest debt first. The numbers are obvious. And yet — you’re still asking.

That’s not a character flaw. That’s your brain doing exactly what brains do when they’re caught between two threats at once. The fact that the logical answer hasn’t been enough to get you moving is data, not failure.

Let’s actually look at what’s happening.

The maths answer (and why it’s incomplete)

The standard financial advice goes like this: if your debt costs 20% interest and your savings earn 4%, you’re losing 16% by saving instead of paying off debt. Therefore, pay the debt.

This is arithmetically correct. It is also, for a large number of people, completely useless.

Not because they’re bad at maths. Because the decision isn’t actually a maths problem. It’s a psychology problem dressed in a spreadsheet.

What debt aversion is actually doing to you

Debt aversion is a well-documented phenomenon in behavioral economics — the finding that people experience debt as psychologically painful in ways that go far beyond the financial cost. Researchers Galai and Sade identified it as a distinct cognitive bias: people will accept a worse financial outcome just to feel less indebted.

This isn’t irrational, exactly. Debt carries social weight, shame, and a sense of lost control that a savings balance — even a small one — can counteract. The problem is when debt aversion becomes so strong that it paralyses you entirely. When the discomfort of looking at the numbers is so loud that you avoid the whole thing.

That’s the trap. Not that you’re choosing wrong. That you stop choosing at all.

Why “just look at the interest rates” misses the point

Here’s what standard financial advice gets wrong about this question: it assumes your goal is to optimise a spreadsheet. But your actual goal — the one driving the anxiety behind the Google search — is to feel safe.

Kahneman and Tversky’s loss aversion research (the foundation of Prospect Theory) showed us that losses feel roughly twice as painful as equivalent gains feel good. Which means that having £0 in savings doesn’t just feel neutral — it feels actively dangerous. Like you’re one broken boiler away from going backwards.

So when someone tells you to throw every spare pound at your debt and keep nothing back, your nervous system registers that as more risk, not less. Even if the maths says otherwise.

This is why so many people follow the “pay off debt first” plan for about three weeks, get hit with an unexpected expense, have nowhere to pull from, and end up back on the credit card. The maths-only approach doesn’t account for the human in the equation.

The goal isn’t to win on paper. The goal is to build a system you’ll actually stay inside.

The behavioural case for doing both (yes, both)

Brad Klontz — one of the leading researchers in financial psychology — has written extensively about how financial behaviour is driven by emotional safety, not logical optimisation. And the clinical reality is this: a small emergency buffer changes everything about how people engage with debt repayment.

When you have nothing saved, every financial decision carries a threat charge. You’re not just paying a bill — you’re gambling that nothing will go wrong between now and next payday. That background anxiety makes it harder to stay consistent, harder to feel any progress, and much easier to give up.

A small savings cushion — even £500 to £1,000 — removes that threat charge. It doesn’t make mathematical sense as a first priority if you’re carrying 30% APR credit card debt. But it makes psychological sense, because it’s what allows you to actually follow through on the rest of the plan.

This is loss framing in action. The frame shifts from “I’m depleting everything to pay debt” (scary) to “I have a buffer and I’m also paying down debt” (manageable). Same money. Different experience. Completely different follow-through rate.

So what’s the actual answer?

Here’s the honest version, not the simplified one:

• If you have no emergency buffer at all: Build a small one first. Not a full three-to-six months. Just enough that an unexpected £300 expense doesn’t derail everything. Then redirect to debt.
• If you have high-interest debt (credit cards, overdrafts, buy-now-pay-later): After that buffer exists, yes — prioritise this over building larger savings. The maths genuinely wins here.
• If your debt is lower-interest (student loan, 0% deals, some car finance): The calculus is less clear-cut, and it’s worth looking at the actual numbers alongside how much psychological weight the debt is carrying for you.
• If you have a workplace pension with employer matching: Always contribute enough to get the full match before doing anything else. That’s a guaranteed 100% return. Nothing on this list beats it.

None of this is one-size-fits-all. And anyone who tells you there’s a single correct answer without knowing your numbers, your income stability, your debt types, or your mental relationship with money — is selling you simplicity you don’t need.

The behavioural debt snowball (and why it works when it shouldn’t)

You may have heard of the debt snowball method — paying off your smallest debt first, regardless of interest rate, to build momentum. Mathematically, this is inferior to the avalanche method (highest interest first). And yet the research, including work by Remi Trudel and colleagues, consistently shows that people who use the snowball method pay off more debt overall.

Why? Because early wins create the psychological experience of progress. Progress feels like safety. Safety reduces avoidance. Reduced avoidance means you actually keep going.

This is the behavioural debt snowball in practice: it’s not the optimal mathematical strategy. It’s the optimal human strategy. And for most people, the human strategy wins, because the mathematical strategy doesn’t account for the fact that you have to live inside it.

The one thing to do this week

Don’t build a budget. Don’t restructure everything. Don’t calculate your debt-to-income ratio at 11pm.

Do this instead: open your banking app and find out exactly what interest rate you’re paying on each debt you have. Just that. Write it down somewhere.

That’s it. You’re not committing to a plan. You’re not deciding anything. You’re just lowering the cost of looking, which is — in behavioral economics terms — the most important first step. You can’t make a good decision with blurry information, and most people are avoiding the numbers precisely because they’re afraid of what they’ll see.

What they usually find is that it’s clearer, and more manageable, than the vague dread made it feel.

One last thing

The reason this question is hard isn’t that you’re bad with money. It’s that you’re being asked to make a calm, rational optimisation decision while your nervous system is treating the whole subject like a threat.

Behavioral economics doesn’t fix that by telling you to try harder. It fixes it by designing around how your brain actually works — building in the wins, the buffers, the frames that make follow-through feel possible rather than punishing.

If you’re curious about why this stuff feels so loaded for you specifically — the patterns underneath the avoidance — the Money Beliefs Quiz is a good place to start. It takes about four minutes and it’ll show you which cognitive patterns are most likely shaping how you think about all of this.

Knowing the pattern is the beginning of working with it.

— Joel