How Much Does It Cost for a Self Assessment Tax Return?

If you are asking how much does it cost for a self assessment tax return, you are probably already weighing up two things at once - the fee itself, and the risk of getting it wrong. For most self-employed people, landlords, subcontractors and company directors, that is the real calculation. It is not just about the cheapest price on paper. It is about whether the return is accurate, filed on time and claiming what you are genuinely entitled to.

The honest answer is that the cost varies. A very straightforward return can be relatively inexpensive. A return involving multiple income sources, CIS deductions, rental property, capital gains or limited company dividends will usually cost more. The price reflects the time needed, the quality of the records and the level of advice wrapped into the service.

How much does it cost for a self assessment tax return in the UK?

In the UK, accountancy fees for a self assessment tax return often start at around £150 to £250 for a simple case, then rise to £300, £500 or more where the affairs are more involved. Some firms charge fixed fees, while others quote based on complexity.

A simple return might cover one source of self-employed income with tidy records and no major adjustments. A more complex return could include employment income, rental income, dividends, subcontractor CIS deductions, pension contributions and expense reviews. That takes longer and carries more responsibility, so the fee rises accordingly.

You may also see very low headline prices advertised. Sometimes those are genuine for basic filing only. Sometimes they assume your books are already complete, your records are clean and no advice is needed. If your paperwork arrives in a carrier bag or your numbers still need sorting, the final bill can look very different.

What affects the cost?

The biggest factor is complexity. HMRC only sees the submitted return, but an accountant sees all the work behind it. If your income comes from one clean source and your records are organised, the job is quicker. If there are gaps, questions or several moving parts, the cost increases because the accountant is doing more than data entry.

Type of income

A sole trader with one trade is usually more straightforward than someone with self-employment, PAYE income and rental property. Landlords may need help with mortgage interest restrictions, allowable costs and joint ownership issues. Directors may need salary and dividend figures pulled together correctly. Subcontractors often need CIS suffered checked carefully to make sure no refund is missed.

Quality of your records

This makes a bigger difference than many people expect. If income and expenses are clearly categorised, invoices are available and bank statements tie in, the return is faster to prepare. If receipts are missing, personal and business spending are mixed together, or figures do not reconcile, more time is needed to get the return into shape.

In practice, better records often mean a lower fee and a stronger return. You are paying for less clean-up work and more useful advice.

Whether bookkeeping is included

Some people think they are paying for a tax return, when in reality they also need bookkeeping support first. If your figures have not been prepared yet, your accountant may need to sort your income, review your expenses and produce the numbers before the return can even be filed.

That is not a hidden extra so much as a separate piece of work. The return is the end product. The records behind it still need to be built properly.

Advice and tax planning

There is also a difference between filing and advising. A budget service may simply submit what you provide. A fuller service should question unusual figures, flag risks, identify allowable expenses and explain what to put aside for tax. That can save money and prevent trouble later, but it takes time and experience.

For many clients, especially those who are newly self-employed or juggling long working hours, that guidance is the part that matters most.

Filing it yourself versus using an accountant

Filing your own return can cost nothing in accountancy fees if your affairs are very simple and you are confident using HMRC's system. For example, someone with a small amount of side income and straightforward records may manage perfectly well alone.

But there are trade-offs. DIY filing saves the fee, yet it puts the responsibility on you to understand deadlines, allowable expenses, payments on account and record-keeping rules. If you underclaim, you may pay too much tax. If you overclaim or make an error, you may face HMRC questions, corrections or penalties.

That is why the cheapest route is not always the least expensive in the round. A decent accountant often earns their fee by spotting claims you would have missed, correcting how income is reported or stopping avoidable mistakes before they happen.

When a low-cost tax return may not be good value

A low fee is attractive, especially if margins are tight. But price on its own does not tell you what you are getting. Some low-cost services are built for volume and only work well if the client has pristine records and no need for discussion. That might suit a straightforward case. It is less suitable if your situation needs judgement.

This matters for groups such as CIS subcontractors, black cab drivers and landlords, where expenses and tax treatment are not always as obvious as they look. Travel, vehicle costs, tools, insurance, use of home, repairs, finance costs and industry-specific claims all need to be handled properly. A rushed or overly generic service may miss the detail.

It is also worth checking whether the quoted fee includes support if HMRC asks questions, whether amendments are covered, and whether the firm will explain your tax bill clearly. A return filed cheaply but badly can become expensive later.

What should be included in the fee?

When comparing quotes, look beyond the number. A proper self assessment service should usually include a review of your income and expenses, preparation of the return, submission to HMRC and confirmation of your tax position. Depending on the firm, it may also include advice on payments on account, reminders about deadlines and help understanding what records to keep next time.

If your affairs are more complex, you may also need related services such as bookkeeping, rental accounts, CIS reconciliation or capital gains calculations. Those are often priced separately, and rightly so, because they involve extra work.

A good accountant should be clear from the start about what is covered. That clarity matters just as much as the fee itself.

Is an accountant worth it for self assessment?

For plenty of people, yes. Not because every return is hugely complicated, but because time is valuable and tax rules are easy to misread. If you are on the road all day, on site from early morning, managing tenants or running a company, your time is usually better spent earning than wrestling with HMRC forms at night.

An accountant is particularly worth considering if you are newly self-employed, have more than one income source, have fallen behind with returns, are claiming a CIS refund or want confidence that your expenses are being handled correctly. In those cases, you are not only paying for submission. You are paying for accuracy, reassurance and fewer unpleasant surprises.

That practical side is why many clients prefer to work with a firm that understands how their trade actually operates. Short And Sons Accountants Ltd, for example, works with self-employed workers, landlords, subcontractors and directors who want clear answers rather than textbook jargon.

How to keep the cost down without cutting corners

The simplest way to reduce the cost of a self assessment tax return is to keep clean records throughout the year. Separate business and personal spending where possible, hold onto receipts, track mileage properly and make sure your figures are not left until the deadline.

Getting organised early helps in two ways. It usually reduces preparation time, and it gives your accountant more room to spot planning opportunities rather than just rushing to file. Leaving everything until January often means more pressure, fewer options and sometimes a higher fee if urgent work is needed.

It also helps to ask the right question when getting a quote. Instead of only asking the price, ask what is included, what information will be needed and whether the fee changes if your records need work. That gives you a fairer comparison.

The real cost is not always the fee

When people ask how much does it cost for a self assessment tax return, they are usually trying to budget sensibly. That makes sense. But the real cost can also include missed expenses, penalties, stress and hours taken away from your work or family.

A fair accountancy fee should buy more than a submitted form. It should give you a return that is accurate, compliant and prepared by someone who understands the practical reality behind the numbers. If that means you know where you stand, claim properly and avoid last-minute panic, it is usually money well spent.

If you are comparing options, look for the service that leaves you clearer, not just cheaper. That is often where the best value sits.