This is one of the most common "which is better" questions I get, and the honest answer is that it depends on your tax position — but for most company owners, the limited company route wins on tax efficiency.
Contributing as a sole trader
As a sole trader you contribute personally to your pension. Under "relief at source", your provider claims basic-rate relief for you, so an £80 net contribution becomes £100 in your pension. If you're a higher-rate taxpayer you claim the extra relief through your Self Assessment return. One useful detail: you get 20% relief even if you're a non-taxpayer with no earnings. The downside is that the contribution doesn't reduce your National Insurance bill, and you're limited by your "relevant UK earnings" — you can't get tax relief on more than you earn in the year.
Contributing through your limited company
Here the company makes an employer contribution directly to your pension. That contribution is a deductible business expense, reducing Corporation Tax, and — importantly — there are no employer or employee National Insurance charges on it at all. For a basic-rate director this usually beats personal contributions: you'd otherwise take salary or dividends, pay tax and NICs on them, and then contribute personally. The company can also contribute even if you've taken little or no salary, because employer contributions aren't limited by your personal earnings (though they must still be "wholly and exclusively" for the business, which is rarely an issue for a director).
The limits that apply to both
Whichever route you use, total contributions are capped by the annual allowance — £60,000 for 2026/27 — and you can carry forward unused allowance from the previous three years. High earners face the tapered annual allowance (it starts to bite once threshold income exceeds £200,000 and adjusted income exceeds £260,000), and once you start flexibly accessing a pension a much lower money purchase annual allowance applies.
Honest verdict
- Basic-rate company owner: company contributions almost always win (CT relief + no NICs).
- Higher-rate sole trader: personal contributions with full Self Assessment relief are still very good.
- Either way, watch the £60,000 annual allowance — and take advice if you're anywhere near the taper.
