£60,000 of Tax Relief Expires on 5 April — Your Pension Should Come First

Put £10,000 into a stocks and shares ISA and you have £10,000 working for you. Put £10,000 into a SIPP and HMRC adds £2,500 — you have £12,500 immediately, before a single investment decision.

For a 40% taxpayer, the same £10,000 contribution only costs £6,000 after claiming higher-rate relief via Self Assessment. That's a 67% instant return on the net cost. No investment in history has offered those odds.

The ISA advocate will argue that ISA withdrawals are tax-free while pension withdrawals are taxed. True — but most retirees have a personal allowance of £12,570 and a state pension of roughly £11,500. That leaves room to withdraw around £1,070 from a private pension completely tax-free, and the next £37,700 at just 20%. If you received 40% relief going in and pay 20% coming out, you've permanently kept the 20% difference.

For anyone exploring how ISA fees interact with this decision, our analysis of flat-fee vs percentage-fee ISA platforms shows that platform costs can erode ISA returns significantly — making the pension's gross tax relief advantage even more decisive.

If you have a workplace pension with employer matching, there is no debate. Your employer must contribute at least 3% of qualifying earnings under auto-enrolment, but many match higher contributions pound for pound up to 5% or even 10%.

A 5% salary sacrifice contribution from someone earning £50,000 means £2,500 from you and £2,500 from your employer. Plus tax relief. Plus National Insurance savings if it's done via salary sacrifice — both you and your employer avoid the 8% employee NI and 15% employer NI on the sacrificed amount. On a £2,500 sacrifice, that's £200 in employee NI savings and £345 in employer NI savings. Some employers pass their NI saving into your pension pot too.

The auto-enrolment minimum of 8% total (5% employee, 3% employer) is widely regarded as insufficient. Our analysis shows that the minimum won't fund a comfortable retirement — you need to contribute more, and doing so through salary sacrifice is the most tax-efficient route available.

No ISA offers employer matching. No ISA offers NI savings. If you're not maxing your employer match before putting a penny into an ISA, you are leaving guaranteed money on the table. This isn't a matter of risk tolerance or investment philosophy. It's arithmetic.

The strongest case for the ISA is access. You can withdraw from a cash ISA tomorrow. A pension locks your money away until age 55 (rising to 57 in 2028).

But most people investing for the long term shouldn't be withdrawing tomorrow. If your emergency fund is sorted — three to six months of expenses in an easy-access account — then the money you're deciding between pension and ISA is, by definition, money you don't need soon.

The lock-up is a feature, not a bug. It protects you from yourself. Behavioural finance research consistently shows that accessible savings get raided — for holidays, cars, kitchen renovations. Pension money stays invested because you can't touch it. Over 20-30 years, that discipline compounds dramatically.

Pensions are also protected from creditors in bankruptcy. ISAs are not. If you're self-employed or running a business, this alone is worth the trade-off. And with the LISA being scrapped, the pension is becoming the only government-backed vehicle that combines tax relief with long-term protection.

The ISA's flexibility also creates a hidden cost: the temptation to optimise rather than commit. Investors who shuffle between cash ISAs and stocks and shares ISAs often end up with lower returns than those who make a single pension contribution and leave it alone.

If you earn between £100,000 and £125,140, your effective marginal tax rate is 60% because the personal allowance tapers away at £1 for every £2 earned above £100,000. Pension contributions reduce your adjusted income, potentially restoring the full allowance.

A £20,000 pension contribution for someone earning £120,000 doesn't just save 40% income tax. It restores £10,000 of personal allowance, saving an additional £4,000 in tax. The effective relief rate is closer to 60%. On that single contribution, you're looking at £12,000 of tax savings — £8,000 from the 40% rate plus £4,000 from restored personal allowance.

With the BoE base rate at 3.75% and inflation running above target, every pound of tax relief matters more. The pension annual allowance of £60,000 plus up to three years of carry-forward can shelter enormous sums. The ISA's £20,000 is generous but cannot compete at these income levels.

For those earning above £260,000 adjusted income, the tapered annual allowance reduces the pension limit — but even the minimum tapered allowance of £10,000 still delivers 45% tax relief. That's a guaranteed £4,500 return on a £10,000 contribution, before any investment growth. The ISA can't match it.

First, check your employer match. If you're not contributing enough to get the full match, increase your contributions immediately — payroll changes can take a pay cycle to process, so do it this week.

Second, if you have a SIPP, work out your remaining annual allowance. Remember you can carry forward unused allowance from 2022/23, 2023/24, and 2024/25 — but the 2022/23 year used the old £40,000 limit. Contact your provider or check your annual pension statement.

Third, for salary sacrifice arrangements, talk to your employer now. The tax year ends on a Saturday this year — payroll teams won't process last-minute requests on 4 April.

Fourth, don't forget the £3,000 CGT allowance that also expires on 5 April. If you're crystallising gains to fund a pension contribution, use the CGT allowance first.

The ISA is a good product. Our complete ISA deadline checklist covers how to use it well. But 'good' isn't 'best'. If you have employer matching available, if you pay higher-rate tax, if you're in the personal allowance taper zone — the pension wins. Use your ISA allowance with whatever is left after maximising pension contributions. For the opposing view, read our Optimizer's case for prioritising the ISA instead.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions.