A Guide to Personal Tax Planning in the UK

Most people in Britain pay more tax than they need to, not because of anything exotic, but because the ordinary things go undone. Allowances lapse unused at midnight on 5 April, savings sit in the wrong wrapper, income is bunched onto one partner when it could be shared, and gains are realised all at once instead of spread across tax years. Personal tax planning is simply the discipline of arranging your money so you keep more of what you earn and grow, using the reliefs Parliament deliberately put in place.

This guide walks through the everyday building blocks, allowances, wrappers, thresholds, couples and retirement sequencing, and where a professional earns their keep. It is general information for the 2026/27 tax year, not personal tax advice; figures should always be checked against current rules, and your own circumstances matter.

Planning, avoidance and evasion

Tax planning means using the allowances and reliefs the law provides to arrange your affairs efficiently, paying an ISA to shelter growth, contributing to a pension for tax relief, sharing assets with a spouse. It is entirely legal and, in most cases, exactly what the rules were designed to encourage. It is different from tax evasion, which is the illegal act of hiding income or misreporting what you owe, and different again from aggressive, artificial avoidance schemes that HMRC increasingly challenges.

The line is easier to see than it sounds. Sensible planning never relies on anything that would not stand up to daylight. If an arrangement sounds artificial, contrived, or simply too good to be true, it very likely is, and the cost of being caught in a disclosed scheme far outweighs any saving. Everything in this guide sits firmly on the right side of that line, and reinforces a broader point: good tax planning is mostly about doing the ordinary things properly and consistently.

Know your annual allowances

Each tax year you are handed a set of allowances, and most of them cannot be carried forward: an allowance you do not use by 5 April is usually gone for good. Knowing what they are, and using them in full, is the foundation everything else is built on. The table below sets out the main personal allowances for 2026/27.

The capital gains exemption is worth dwelling on: at £3,000 it is a fraction of what it was a few years ago, which makes deliberately spreading disposals across tax years, and using both partners’ exemptions, far more valuable than it used to be. Where you hold investments outside a wrapper, timing when you crystallise gains, and offsetting losses against gains in the same year, keeps more of your return in your hands.

A useful exception to the “use it or lose it” rule is pension carry-forward: unused annual allowance from the previous three tax years can be added to this year’s £60,000, provided you were a pension member in those years and have the earnings to support it. That can matter enormously in a year of unusually high income, a bonus, a business sale, or a good trading year, when a single large contribution can sweep a lot of income out of higher-rate tax at once. It is one of the few allowances that rewards planning ahead rather than acting only at year end.

The wrappers that do the heavy lifting

ISAs and pensions are the workhorses of tax-efficient saving. An ISA shelters up to £20,000 a year, with no tax on the growth, the income it produces, or the money you take out. A pension attracts tax relief at your marginal rate on the way in, so a £100 contribution costs a higher-rate taxpayer just £60, and grows free of income and capital gains tax, in exchange for being locked away until at least 55 (rising to 57 from 2028). You can find the detail of pension limits in our note on how much you can pay into a pension tax-free.

The two are complementary rather than competing. A pension is unbeatable for reducing taxable income now, especially if a contribution drags you back below an awkward threshold; an ISA gives you flexible, tax-free money you can reach at any age. Many people use the pension for long-term retirement saving and the ISA for medium-term goals and a tax-free income top-up later. Coordinating them, alongside your other assets, is a natural bridge into broader wealth management.

Mind the awkward thresholds

The UK system has several points where earning a little more costs a lot, and knowing where they sit is half the battle. The best known is the £100,000 mark: above it, your personal allowance is withdrawn by £1 for every £2 earned, creating an effective marginal rate of around 60% on income between £100,000 and £125,140. A pension contribution that brings taxable income back below £100,000 therefore reclaims both the lost allowance and higher-rate relief, one of the most efficient moves in personal tax.

Other cliff-edges work the same way: the High Income Child Benefit Charge claws back Child Benefit above a set income, and the pension annual allowance itself tapers for very high earners. None of these is a reason to earn less, but each is a reason to think about how income is taken, and whether pension contributions or timing can keep you the right side of the edge.

Plan as a couple, not two individuals

For couples, the household, not the individual, is usually the right unit for tax planning. Each person has their own personal allowance, savings and dividend allowances, capital gains exemption and set of tax bands. Shifting income-producing assets towards the lower earner can mean the same family income is taxed far more lightly, because it is spread across two sets of allowances and lower-rate bands rather than piled onto one high rate.

What makes this practical is that transfers of assets between spouses and civil partners are generally free of both income tax and capital gains tax. That turns a potentially clunky rearrangement into a simple one. The Marriage Allowance is a smaller but frequently missed win, letting a non-taxpayer hand £1,260 of unused personal allowance to a basic-rate partner. Used consistently, both ISAs filled every year, savings held in the lower earner’s name, these steps quietly compound into meaningful savings over time.

Sequencing income in retirement

How you draw income in retirement has a real effect on your tax bill. Because ISA withdrawals are tax-free while most pension income is taxable, and because the 25% tax-free pension element can be phased rather than taken all at once, there is genuine scope to shape your income so you use your personal allowance and basic-rate band each year without tipping into higher-rate tax. Drawing a little from several pots, rather than emptying one, is often the tax-efficient path.

Sequencing withdrawals well is a classic example of planning that pays for itself, sometimes several thousand pounds a year over a long retirement. It also interacts with inheritance tax: from April 2027, unused pension funds are due to fall within the scope of IHT, which changes the calculus of what to spend first. That makes it worth looking at alongside your wider estate: our complete guide to inheritance tax planning covers how the pieces connect.

The order also matters for keeping below the thresholds that follow you into retirement. Taking too much taxable pension income in one year can push you into higher-rate tax, restrict your personal savings allowance, or in some cases trigger the loss of your personal allowance all over again. Blending a tax-free ISA withdrawal, the 25% tax-free pension element and a measured slice of taxable income each year is how experienced planners smooth a retirement income and keep the tax bill low, a small amount of arithmetic each year that quietly adds up to a great deal over two or three decades.

DIY or a coordinated plan?

Plenty of tax planning is genuinely do-it-yourself: filling your ISA, claiming Marriage Allowance, keeping an eye on the £100,000 threshold. Where a professional earns their fee is in coordination, weaving pensions, investments, allowances and the timing of income into one coherent, tax-aware plan, and working alongside an accountant where a return needs filing or a business is involved.

• 1

  Fill your ISA before 5 April

  The £20,000 allowance cannot be carried forward: an unused ISA allowance is lost at year end.

• 2

  Top up pensions to reclaim relief

  Especially if a contribution pulls you below £100,000 or £50,270 and reclaims higher-rate relief.

• 3

  Use both partners’ allowances

  Move savings and investments to the lower earner and claim Marriage Allowance where eligible.

• 4

  Bank your capital gains exemption

  Realise gains up to £3,000 each, and pair gains with losses to offset within the year.

• 5

  Diarise the awkward thresholds

  Check income against £100,000 and the Child Benefit charge before year end, while there is still time to act.