The order of operations

Where to put the next pound. The sequence that stops the most expensive mistakes.

"Should I put money in a pension or an ISA?" is usually the wrong first question, because for most people there are three or four things that should happen before either.

There's a rough order that works for most people most of the time. It isn't a rule, and the last steps genuinely depend on circumstances — but the early ones are close to universal, and getting them out of sequence costs real money.

Step 0: know what's actually happening

Before anything else, know what comes in and what goes out. Three months of bank statements, sorted into essentials and everything else.

This is dull and it's the step people skip. It's also the only way to know how much you have to work with, and it routinely surfaces subscriptions, insurances and standing orders nobody has looked at in years.

Step 1: a small buffer

Somewhere around £1,000, in an instant access account, before anything else.

The point isn't to cover a real emergency — it's to stop a small unexpected cost putting you on a credit card. A broken boiler at this stage undoes months of progress if there's nothing behind you.

Step 2: clear expensive debt

Credit cards, overdrafts, store cards, payday loans. Anything charging a high rate.

Paying off debt at 22% is a guaranteed 22% return, tax-free, with no risk. Nothing you can invest in reliably beats that. Someone investing at an expected 6% while carrying credit card debt at 22% is losing money with every contribution.

Two approaches: highest rate first, which is mathematically optimal, or smallest balance first, which is slower but produces visible wins and keeps people going. The best method is the one you'll finish.

Not all debt is expensive. Mortgages, student loans and 0% car finance are a different question, covered below and in Overpay the mortgage or invest?.

Step 3: take the employer match

If your employer will match more pension contributions than you're currently making, contribute enough to get the full match before doing anything else with the money.

This is an immediate 100% return, before tax relief is even counted. There is nothing else on this list that comes close, and no investment anywhere that reliably matches it.

Plenty of people don't know what their employer offers. One email to HR answers it — see How much should you be paying in?.

Step 4: build the real emergency fund

Three to six months of essential spending, in cash, accessible. More if your income is variable or your household depends on one earner.

This is the foundation everything else stands on. Without it, the first serious setback forces you to sell investments at a bad moment or borrow expensively. Your emergency fund covers how much and where to keep it.

Step 5: cover the disasters

If anyone depends on your income, or if you'd be in trouble unable to work, protection belongs here — before optimising longer-term savings.

A perfect retirement plan is worth nothing if illness stops your income three years in. This step is skipped more than any other, and it's the one that turns a setback into a catastrophe. See Where to start with protection.

Step 6: then the interesting question

Only now does pension versus ISA versus mortgage overpayment become the live question. And here the answer genuinely depends.

Pension wins on tax, especially for higher-rate taxpayers, and especially for anyone whose income touches the 60% band or the Child Benefit charge, where the effective relief is extraordinary. The cost is access — nothing until 55, rising to 57 in 2028.

ISA wins on flexibility. Tax-free growth, tax-free withdrawals, available whenever you want. Better for anything you might need before retirement, and for anyone who values being able to change their mind.

Mortgage overpayment is a guaranteed, risk-free return equal to your mortgage rate. Its attractiveness depends heavily on that rate — see Overpay the mortgage or invest?.

Most people end up doing some of each rather than choosing one.

Where the order changes

Saving for a first home? A Lifetime ISA's 25% bonus is hard to beat for that specific purpose, and it may reasonably jump ahead of general pension contributions above the employer match.

Income near £100,000 or near £60,000 with children? Pension contributions become worth far more than their headline relief, and may justify moving up the order.

Student loans usually shouldn't be overpaid. Repayment is income-contingent and the balance is written off eventually, so for many people overpaying is voluntarily paying a debt that would have expired.

Self-employed? The emergency fund matters more and should probably be larger, because there's no sick pay behind you.

Approaching retirement? The sequence changes entirely — that's Retirement income.

The honest summary

Steps 1 to 5 are close to universal and mostly uncontroversial. Step 6 is where the interesting discussion happens, and it's also where people start before they've done the rest.

If you're arguing about pension versus ISA while carrying credit card debt and no emergency fund, you're optimising the wrong end of the problem.

This article is for general education only and isn't personal advice. The right order depends on your circumstances.