What accounting do consultants actually need to worry about? It’s a fair question, and the honest answer is: less than you might fear, but more than just filing a tax return once a year.

Why Consulting Income Needs Treating Differently

Most accounting guides are written with product businesses or regular employees in mind. Consulting doesn’t fit that mould. Your income is project-based, often lumpy, sometimes a mix of retainers and one-off fees, and almost always comes without anyone deducting tax at source.

That last point matters a lot. When you were employed, your employer handled PAYE, National Insurance and pension contributions before you ever saw the money. As a consultant, you receive the full amount and it’s on you to set aside what you owe HMRC. This is where most people come unstuck in their first year or two.

The Core Accounting Tasks You Need to Stay On Top Of

Self Assessment is the starting point. If you earn income outside of PAYE, you need to register with HMRC and file a tax return each year. For most consultants operating as sole traders, this covers your profits, any allowable expenses you’re claiming, and any other income sources. The filing deadline for online returns is 31 January following the end of the tax year.

Expenses are where consultants often leave money on the table. HMRC allows you to reduce your tax bill by claiming business expenses, and as a consultant those can include professional subscriptions, home office costs, travel to client sites, software and equipment. The rule is simple: if the cost was wholly and exclusively for the purpose of your business, it’s likely claimable.

VAT, Thresholds and What Happens When You Grow

VAT registration becomes compulsory once your taxable turnover crosses the current threshold, which sits at £90,000. If your consulting fees are heading toward that number, you need to be watching it. The moment you cross it, you have 30 days to register or you risk a penalty from HMRC.

Some consultants benefit from registering voluntarily before they hit the threshold. If your clients are VAT-registered businesses themselves, they can reclaim the VAT you charge, so it costs them nothing extra. And you get to reclaim VAT on your own purchases. It’s worth doing the numbers rather than just assuming registration is a problem to delay.

Sole Trader or Limited Company, and the IR35 Question

At some point, most consultants ask whether they should be operating through a limited company. The answer depends on your profit level, your client base and how you work. A limited company can be more tax-efficient above a certain income level, but it brings more reporting responsibilities and, critically, it brings IR35 into the picture.

The off-payroll working rules, known as IR35, exist to make sure that contractors and consultants who work like employees pay broadly the same tax as employees would. The rules apply contract by contract, so you could have some work that falls inside IR35 and some that doesn’t. HMRC’s CEST tool can help you check employment status for tax purposes, though getting proper advice before you set anything up is usually the smarter move. If a client determines you’re inside IR35 for a contract, they become responsible for deducting Income Tax and National Insurance from what they pay your company.