Sole trader and limited company Q&A

Not necessarily. The trading allowance lets you earn up to £1,000 in gross self-employment income in a tax year before you need to register with HMRC or pay tax on it. Go over that and you need to register for self-assessment, even if you don't end up owing anything after expenses.

The obvious ones (stock, tools, software) rarely get missed. It's the smaller, ongoing ones that add up over a year: a proportion of home costs if you work from home (heating, broadband, council tax), mileage at HMRC's approved rates rather than fuel receipts, a proportion of your phone bill, and professional subscriptions or trade memberships relevant to your work.

For most sole traders with one vehicle used partly for business, HMRC's simplified mileage rate is easier to track and often comes out similar or better than working out actual running costs, fuel, insurance and a business-use percentage. It's worth comparing both in your first year to see which suits how you use the vehicle.

Pension contributions reduce your taxable profit, so they're one of the more effective ways to bring down your Income Tax bill while building something for later — especially useful in a year where profits push you into a higher tax band. It's worth timing contributions around your year-end once you know roughly what you'll earn.

If your spouse or civil partner earns below the personal allowance and you're a basic rate taxpayer, the marriage allowance lets them transfer part of their unused allowance to you — a modest but genuinely free reduction in your tax bill for a five-minute application.

Once your taxable turnover goes over £90,000 in any rolling 12-month period (not just your tax year), registration becomes compulsory. Some sole traders register voluntarily before that if most of their customers are VAT-registered businesses themselves, since it doesn't make you less competitive to them and lets you reclaim VAT on purchases.

There's no single profit figure where it "switches" — it depends on how much you draw out to live on versus leave in the business, your appetite for the extra admin, and what you're saving toward. As a rough starting point, it's worth a proper conversation once profits are consistently well above what you personally need to live on.

Most owner-directors take a small salary (often around the National Insurance threshold, so it counts toward your state pension without triggering NI) and top up income with dividends, which are taxed more favourably than salary above that point. The first £500 of dividends is also tax-free each year. The exact split depends on your other income and what the company can afford — worth reviewing every year, not just setting once.

Profits up to £50,000 are taxed at 19%, profits above £250,000 at 25%, and anything in between uses marginal relief which tapers gradually — so most small limited companies aren't paying a flat 25% even if that's the headline rate people quote. Knowing which band you're in matters for timing things like equipment purchases or bonus payments.

Annual Investment Allowance lets you deduct the full cost of most equipment and machinery from profits in the year you buy it, rather than spreading it over several years. If you're close to a year-end and were planning a purchase anyway, timing it before rather than after can bring the tax relief forward by a full year.

Yes — employer pension contributions are usually more tax-efficient than paying in personally, since they come straight out of company profits before Corporation Tax and don't count as a taxable benefit to you, as long as they're within the usual annual limits.

HMRC allows small gifts to directors and staff (up to £50 each, capped per director each tax year) — think a birthday gift or a Christmas hamper — without it counting as a taxable benefit or needing to go through payroll, as long as it's not cash and not a reward tied to performance.

Not necessarily a downside, but it's worth a plan rather than letting it sit by default — whether that's extracting it tax-efficiently over several years, reinvesting it in the business, or, further down the line, considerations like Business Asset Disposal Relief if you're ever looking to sell or wind the company up.

Director's loans are allowed but come with rules: go over £10,000 and it can be treated as a benefit in kind, and if it's not repaid within nine months of the company's year-end, the company faces an additional tax charge on the outstanding amount. Worth flagging any director's loan to us as soon as it happens, not at year-end.

Instead of tracking VAT on every purchase and sale, you pay HMRC a single fixed percentage of your turnover based on your trade sector, and you get a 1% discount in your first year of registration. It works best for businesses with low purchase costs — if you spend a lot on VAT-rated stock or materials, standard VAT accounting usually works out better.

If your spending on goods (not services) is below 2% of your turnover, or under £1,000 a year, HMRC treats you as a "limited cost trader" and applies a 16.5% flat rate regardless of your actual trade sector — which removes most of the benefit of the scheme for a lot of consultants and service-based businesses. Worth checking before assuming the scheme suits you.

If most of your customers are VAT-registered businesses who can reclaim the VAT you charge them, voluntary registration can be worth it — it lets you reclaim VAT on your own purchases and can look more established. If your customers are mainly the public, registering early just makes you more expensive with no upside.

Standard VAT accounting is based on invoice dates — you pay VAT on sales you've invoiced even if the customer hasn't paid you yet. Cash accounting means you only pay VAT once you've actually been paid, which can help cash flow considerably if customers are slow to pay, as long as your turnover is under the scheme's threshold.

For self-assessment, it's an immediate £100 penalty even if you owe nothing, rising the longer it's left. For company accounts and Corporation Tax returns, late filing penalties increased significantly from April 2026, so what used to be a manageable fine for being a few weeks late now carries much more bite.

MTD requires VAT-registered businesses to keep digital records and file returns through compatible software rather than manually — this already applies to VAT. It's being extended to income tax for higher-earning sole traders and landlords, so if that's you, it's worth getting set up on the right software well ahead of your mandation date rather than scrambling at the deadline.

Honestly, it depends on your time and how comfortable you are with the rules changing every year. Most clients find the fee pays for itself in expenses they'd have missed, penalties they'd have avoided, and time back to spend on the actual business rather than paperwork — but for a very simple, very small setup, DIY can work fine too. Use the calculator to get a feel for where you sit.