Review My Self Assessment Tax Return

That moment usually comes late at night. You have entered the figures, HMRC says the return is nearly ready, and one thought keeps nagging away - should someone review my self-assessment tax return before I press submit?

For a lot of self-employed people, landlords, subcontractors and directors, that is the right question to ask. A tax return can look finished and still contain missed expenses, incorrect treatment of income, or figures that do not quite tie up with what HMRC already knows. A proper review is not about making things look more complicated than they are. It is about checking that the return is accurate, reasonable and not costing you money unnecessarily.

Why people ask someone to review my self-assessment tax return

Most people do not want a lecture on tax law. They want to know two things - have I done this properly, and am I paying more tax than I need to?

That is where a review earns its keep. If you are busy earning, driving, managing jobs, collecting rent or running a small company, it is easy to treat the tax return as an admin task to get out of the way. The trouble is that small mistakes can have expensive consequences. Some lead to overpaying tax. Others create HMRC queries later, which means more time spent digging out records and explaining figures months after you thought the job was done.

For sole traders, one of the biggest risks is expense claims. People often underclaim because they are unsure what counts. We regularly see travel, phone use, tools, insurance, accountancy fees, and use of home costs left out completely or claimed inconsistently. Landlords face a different set of issues, especially around mortgage interest restriction, repairs versus improvements, and jointly owned properties. CIS subcontractors often have another problem - the return may be accurate on income but fail to reflect all the tax already deducted at source, which can mean refunds are missed or delayed.

What a proper tax return review should cover

If you ask an accountant to review your self-assessment tax return, the value is in the detail. It is not just a quick glance over the final number.

Income checks

The first job is making sure all sources of income have been treated correctly. That sounds obvious, but this is where plenty of returns go wrong. Self-employed income, CIS statements, rental income, dividends, PAYE earnings and interest can all interact in ways that affect the final tax position.

For example, a subcontractor may have CIS suffered that needs to be matched against turnover properly. A limited company director may need salary and dividends reported in the right places. A landlord with more than one property may have allowable costs spread incorrectly. If the income is wrong at the start, the whole return is built on shaky ground.

Expense and relief checks

This is usually where the review makes the biggest difference. It is not about being aggressive. It is about being fair and accurate.

An experienced accountant will look at whether expenses are wholly and exclusively for the business, whether capital items have been dealt with correctly, and whether available reliefs have been missed. Sometimes the issue is underclaiming. Sometimes it is overclaiming something that should not be there. Both matter.

There is always a balance to strike. A cautious approach may reduce HMRC risk but leave money on the table. An overly optimistic approach can create trouble later. Good advice sits in the middle - practical, defensible and based on the facts.

Compliance checks

A review should also consider whether the return matches the wider compliance picture. Do the figures agree with bookkeeping records? Have payments on account been factored in properly? Does the return sit sensibly alongside VAT records, payroll figures, or company accounts where relevant?

This matters more than many people realise. HMRC systems are better at spotting inconsistencies than they used to be. If one set of numbers says one thing and another says something else, it increases the chance of questions being asked.

Common mistakes we see before submission

When people say, "can you review my self-assessment tax return", the errors are often familiar.

One is simple omission. A client forgets bank interest, a small PAYE job, or rental income from part of the year. Another is using rough figures when exact records were available but not pulled together properly. That can be risky if the estimates are not reasonable.

Expense mistakes are common too. Motor costs are a classic example. Some people claim fuel but forget insurance and servicing. Others mix private and business use without any sensible adjustment. Home office claims are another area where people are either too timid or too generous.

For landlords, we often see confusion between a repair and an improvement. Replacing a broken boiler with a modern equivalent may be a repair in many cases. Adding a much higher specification system as part of a wider upgrade may be treated differently. The facts matter.

For directors and shareholders, dividends can cause trouble if the paperwork and accounting do not support what has been reported. If you have taken money out of the company, it is worth being sure it has been categorised properly before the return goes in.

When a review is especially worth doing

Not every return carries the same level of risk. If you have one source of PAYE income and very little else, the review may be straightforward. If you have multiple income streams, changing circumstances, or a business with lots of moving parts, the case for review is much stronger.

You are filing for the first time

First returns often contain avoidable mistakes because people do not yet know what HMRC expects. Registration dates, basis periods, allowable expenses and payments on account can all catch people out.

Your income has changed

If profits have gone up sharply, if you started renting out property, if you moved from employment into self-employment, or if you stopped trading during the year, a review can help make sure the return reflects that change properly.

You work in trades or under CIS

Construction industry clients often have complex records, multiple contractors and tax already deducted. This is exactly the sort of area where a careful review can prevent refunds being missed and figures being duplicated or understated.

You are close to the deadline

Late January filings are often rushed filings. The closer you are to the deadline, the more likely it is that something has been entered for speed rather than accuracy. That does not always mean the return is wrong, but it is a good reason to get a second pair of eyes on it.

What to have ready if you want someone to review my self-assessment tax return

The smoother the process, the faster someone can tell you whether the return is in good shape.

Usually that means having your draft tax return, bookkeeping summary or income records, details of expenses claimed, CIS statements if relevant, rental statements if you are a landlord, and any P60s, P45s, dividend vouchers or interest certificates. If there is something unusual, say so upfront. Selling an asset, receiving a grant, changing business structure or taking on a company vehicle can all affect the right treatment.

You do not need to present everything perfectly. A good accountant is used to sorting through working paperwork. What matters is that the information is complete enough to form a clear picture.

What a review can and cannot do

A review can improve accuracy, highlight missed claims, reduce the chance of HMRC problems and give you confidence before submission. It can also show that your original draft was largely fine, which is still useful. Peace of mind has value, especially when tax bills are involved.

What it cannot do is magic away poor records or invent expenses that were never incurred. If your paperwork is incomplete, some areas may still need estimates or further evidence. If the return has already been filed and errors are discovered later, that moves into amendment territory rather than pre-submission review.

That is why timing matters. The best time to have a return checked is before it goes in, while changes can still be made cleanly and calmly.

Choosing the right accountant to review a self-assessment tax return

Technical knowledge matters, but so does practical understanding. If your accountant works with people like you every day, they are more likely to spot what is ordinary in your trade, what needs extra care, and where tax planning opportunities usually sit.

That is especially true for self-employed workers and small businesses. A black cab driver, a subcontractor and a landlord can all file self-assessment returns, but the detail behind each one is very different. You want someone who understands the paperwork, the working pattern and the common tax issues that come with your line of work.

At Short And Sons Accountants Ltd, that practical grounding is a big part of how we work. Clients do not need more jargon. They need clear answers, accurate returns and the confidence that someone has checked the numbers properly.

If you are hesitating over the submit button, trust that instinct. A tax return should not just be filed - it should stand up to scrutiny and make proper use of the reliefs available to you.