When you work for yourself, one of the biggest financial choices is where to save. Most people compare the benefits of a pension against an ISA.
A pension provides tax relief on the way in and is designed to provide an income during retirement. An ISA provides clean, penalty-free access at any time, making it suitable for both short-term and medium-term needs.
Pensions and ISAs do different things. A pension normally gives you tax relief on contributions but locks the money away until pension age. An ISA gives you no upfront tax relief, but withdrawals are tax-free, and you can normally access the money whenever you need it.
This isn’t just a personal finance question. As we reported in New report calls for HMRC nudges to boost self-employed pensions and Government relaunches Pensions Commission as millions of self-employed fall behind, policymakers know that too few self-employed people are saving enough.
If you’re worried that you haven’t started saving for your retirement yet, our guide It’s never too late to start saving for a pension is a good place to start.
Pensions vs ISAs – the main differences
| Feature | Pension (SIPP or personal pension) | ISA (Cash or Stocks & Shares) |
|---|---|---|
| Tax relief on contributions | Yes. Personal contributions can normally receive tax relief up to 100% of your relevant UK earnings, subject to the pension allowance rules. Basic-rate relief is usually added at source, with further relief potentially available to higher and additional-rate taxpayers (HMRC). | No tax relief when you pay in. Growth and withdrawals are tax free (GOV.UK ISA guide). |
| Tax on growth and withdrawals | Growth is normally tax free inside the pension. From access age you can usually take up to 25% tax free, subject to the lump sum allowance, with the remainder generally taxed as income when withdrawn (HMRC). | Growth and withdrawals are tax free. No income tax or capital gains tax inside an ISA. |
| Access | Not normally before age 55, rising to 57 on 6 April 2028 (policy note). | Anytime, subject to the provider’s terms. If your ISA is “flexible,” you can withdraw and replace money in the same tax year without using more of your annual allowance. |
| Annual limits | The standard annual allowance is £60,000 for most people, although tapering or the money purchase annual allowance can reduce it (HMRC). | ISA allowance £20,000 per tax year across all ISAs combined. |
| Best use case | Long-term retirement saving where the tax relief is valuable. | Savings you may want access to before retirement. |
Worked examples
Jane – steady income, basic rate taxpayer. Jane runs a design business earning £40,000. She pays £160 a month from her own pocket into a pension. Basic-rate tax relief increases this to £200 in her pension.
If she instead put the same £160 a month into an ISA, she would invest £ 160. The pension therefore starts with an advantage because of the tax relief, although pension withdrawals may later be subject to Income Tax.
Sam – irregular earnings, needs flexibility. Sam is a photographer whose income fluctuates significantly. He keeps £12,000 in a Stocks & Shares ISA, giving him a cushion for tax bills and quieter months. When he completes a large commission, he puts £3,000 into a pension. This mix gives him accessible savings plus long-term funds locked away for retirement.
Amira – consultant on higher rate tax. Amira earns £90,000. She makes a £500 gross monthly pension contribution. Assuming the whole contribution qualifies for higher-rate relief, its eventual net cost to her is £300 after claiming the additional relief.
She still uses an ISA for short-term savings, but the pension gives her more tax relief on money she is prepared to leave invested until retirement. The final comparison will also depend on investment returns and the tax she pays when she withdraws pension income.
How to combine both, in practice
1. Set a pension baseline. Even modest regular contributions matter. For many self-employed people, a popular option is a SIPP, which gives flexibility over providers and investments. Our main guide – how do pensions work if you’re a sole trader – explains the mechanics, and our simple guide to SIPPs covers how they work in practice.
2. Build an ISA safety net. Aim for three to six months of essential costs in accessible savings, so you are not relying on money locked away in a pension. A Cash ISA suits short-term cash reserves, while a Stocks & Shares ISA is generally better for money you can keep invested longer.
If you want that buffer to earn interest while it sits there, a flexible Individual Savings Account pays a variable rate on the full balance with no account fees and lets you withdraw and replace money within the same tax year.
3. Use lump sums in a smart way. If you have an excellent quarter or secure a one-off contract, consider splitting the money. Putting some into your ISA gives you a safety buffer you can reach if needed, while paying some into your pension secures the available tax relief for the long term.
4. Review each year. As profits rise, consider increasing pension contributions within the relevant limits. If you start taking taxable income flexibly from a defined contribution pension in the future, the money purchase annual allowance may restrict how much you can subsequently contribute with the benefit of the normal annual allowance.
Key rules to know
- Tax relief on contributions. Tax relief on personal pension contributions is normally available up to 100% of your relevant UK earnings, subject to the pension allowance rules. Basic-rate relief is normally added automatically if your scheme uses relief at source. Higher and additional-rate taxpayers may be able to claim further relief.
- Annual allowance. The standard annual allowance is £60,000 a year for most people. The tapered annual allowance can apply where threshold income exceeds £200,000 and adjusted income exceeds £260,000. If the money purchase annual allowance has been triggered, the allowance for money purchase pension contributions is £10,000.
- Access age. You cannot usually take money out before age 55. This rises to 57 on 6 April 2028. Limited exceptions apply, including some cases of ill health.
- ISA allowance. You can save up to £20,000 each tax year across your ISAs. Flexible ISAs allow you to replace withdrawals within the same tax year without using additional allowance.
- Tax-free pension cash. When you access your pension, you can normally take up to 25% tax free. The standard lump sum allowance is £268,275, although some people have protected rights to a higher amount.
Find out more about SIPPs and ISAs
If you’re looking for a provider that offers both SIPPs and ISAs in one place, take a look at interactive investor. Their platform is popular with self-employed savers who want the flexibility to manage pension and ISA investments side by side.
FAQs
Is a pension or an ISA better for retirement?
A pension normally has the advantage of tax relief on contributions, while an ISA gives you much greater flexibility because withdrawals are tax free and the money is accessible before retirement. Many self-employed people use both.
Can I move ISA money into a pension?
You can’t transfer directly from an ISA into a pension. You can withdraw money from an ISA and make a pension contribution, subject to the pension contribution and tax-relief rules that apply to you.
How do I claim higher rate relief?
If your scheme uses relief at source, you can normally claim higher or additional rate relief through Self Assessment or directly from HMRC, depending on your circumstances.
What about a Lifetime ISA?
You can use a Lifetime ISA for a first home or later life. You can contribute up to £4,000 a year, which counts towards your overall £20,000 ISA allowance, and the government adds a 25% bonus.
Withdrawals for purposes other than an eligible first-home purchase or after age 60 are normally subject to a 25% withdrawal charge, subject to limited exceptions.
What is the Money Purchase Annual Allowance?
The Money Purchase Annual Allowance can be triggered when you flexibly access taxable benefits from a defined contribution pension. Once triggered, the annual allowance for money purchase contributions is normally reduced to £10,000. Taking tax-free cash alone does not always trigger the MPAA.
The information here is general. Pension and ISA rules can change, and the right choice will depend on your own finances. Check the current rules before acting, and take regulated advice if you need it.