How does accounting work for freelancers? It’s a question I get asked a lot, and the honest answer is: it’s simpler than most people fear, but only if you know what you’re actually supposed to be doing.

What Do Freelancers Actually Need to Track?

If you’re self-employed and earning money, you need to keep a record of what comes in and what goes out. That means every payment from a client, every business expense, and every invoice you raise. You don’t need a complicated system for this, especially early on.

The key things to track are your income (what clients pay you), your allowable expenses (things you genuinely spend money on to run your business, like software, a home office proportion, travel), and any receipts that back those figures up. HMRC can ask to see your records going back up to six years, so keeping them in one place from the start saves a lot of stress later. A simple spreadsheet is fine when you’re starting out. Many freelancers eventually move to accounting software like FreeAgent or QuickBooks, but there’s no legal requirement to use any particular tool right now.

Self Assessment: What It Is and How It Works for Freelancers

Self Assessment is how you report your freelance income to HMRC and pay the tax you owe. If you earned more than £1,000 from self-employment in a tax year (April to April), you need to register for Self Assessment and file a tax return. Most freelancers I speak to already know this but aren’t always sure what to do about it.

You register with HMRC, they give you a Unique Taxpayer Reference (UTR), and each year you file a return showing your income and expenses. HMRC calculates what tax you owe, and you pay it. The main deadlines are 31 January for online filing and payment, and 31 July for any payment on account (an upfront payment towards next year’s bill). Miss the 31 January deadline and you’ll get a £100 fixed penalty straight away, even if you don’t owe any tax. That penalty grows the longer you leave it.

The Mistakes Most Freelancers Make (and How to Avoid Them)

The biggest one I see is not putting tax aside as you earn. Unlike employment, no one deducts tax from your freelance payments. By the time January comes around, some freelancers owe more than they’ve saved. A rough rule of thumb is to put aside around 20-25% of your profit as you go, and keep it in a separate account so you’re not tempted to spend it.

The second most common mistake is not claiming expenses you’re actually entitled to. Things like a portion of your home broadband, professional subscriptions, equipment, mileage, and training costs can all reduce your tax bill. HMRC publishes guidance on what counts as an allowable expense, and it’s worth reading if you haven’t already. The third mistake is leaving everything to the last minute. Filing in January when you’ve barely looked at your records since April is stressful and costly.

Do You Actually Need an Accountant as a Freelancer?

Not everyone does, and I’d be giving you bad advice if I said otherwise. If your freelance work is simple, your income is straightforward, and you’re comfortable working through the numbers yourself, you can absolutely file your own Self Assessment. Plenty of people do it every year without help.

Where an accountant earns their fee is in claiming expenses you didn’t know about, spotting errors before HMRC does, and saving you the time and anxiety of doing it yourself. As of early 2026, there were around 4.57 million self-employed workers in the UK. Many manage fine alone. Many others reach a point where the time cost, the complexity, or simply the stress of it isn’t worth it anymore. There’s no shame in either path.