What to Know About HMRC Reviews: Why Complete and Accurate Information Matters
As your accountant, our role is to prepare and submit tax returns that are accurate, complete, and compliant with HMRC’s rules. To do that properly, we rely entirely on the information you provide to us.
Recently, we have been involved in HMRC reviews where earlier tax returns were examined over several years. In these cases, HMRC identified issues that arose because information was missing or incorrect when the returns were originally submitted. Examples included income that had not been disclosed, pension contributions that were reported but not actually paid, and changes in circumstances that were not communicated at the time.
This blog explains why providing full and accurate information is so important, how HMRC’s review process works, what the potential consequences can be, and what we need from you to reduce risk, cost, and stress.
Responsibilities: Ours and Yours
HMRC makes it clear that the legal responsibility for a tax return always rests with the taxpayer, even when an accountant or agent submits that return on their behalf.
We prepare returns based on the information you give us. We do not have independent access to all aspects of your financial life unless you tell us about them and provide supporting evidence. HMRC expects taxpayers to take reasonable care to make sure returns are accurate and complete. If information is missing or incorrect, HMRC may conclude that reasonable care has not been taken — even where there was no intention to mislead.
What Happens During an HMRC Compliance Check?
HMRC refers to reviews or investigations as compliance checks. These can apply to:
Self Assessment tax returns
VAT returns
Corporation Tax
PAYE and other business taxes
A compliance check does not automatically mean something wrong has occurred. It is HMRC’s way of checking that the correct tax has been paid.
Typically, HMRC will:
Write to the taxpayer (and their agent) explaining what they are reviewing
Ask for documents and explanations
Review several years of information if necessary
Ask follow‑up questions
Issue an outcome confirming either no issues, or additional tax, interest, and possibly penalties
HMRC can look back several years, depending on the nature of the issue they identify.
How HMRC Identifies Issues
HMRC uses a wide range of information when reviewing tax returns, including:
Information already held by HMRC (PAYE data, bank interest, pension records)
Data from third parties i.e. property rental companies etc
Publicly available information, where relevant
This may include business websites, online platforms, and other publicly accessible sources if they help HMRC establish the facts. It is therefore essential that tax returns reflect reality accurately and consistently.
Penalties, Interest, and Additional Costs
If HMRC finds that a return is incorrect, the financial consequences may include:
Additional tax due
Interest on unpaid tax
Penalties, depending on whether HMRC believes the error was careless or deliberate
Penalties and interest can arise even where mistakes were unintentional.
Additional Professional Fees
Where HMRC opens a compliance check or investigation, there is additional professional work required. This may include:
Reviewing historic records
Responding to HMRC information notices
Preparing explanations and reconciliations
Corresponding with HMRC over extended periods
This work is outside the scope of standard compliance services and, in line with our engagement terms, may result in additional fees.
The best way to avoid these costs is to:
Provide all relevant information upfront
Communicate changes in your tax affairs as they happen
Respond quickly to HMRC correspondence
Communication Is Key: Tell Us the Full Story
Tax returns are not just numbers — they reflect what has actually happened during the year. Like a story.
Please tell us if anything has changed or occurred, such as:
Changing jobs or having multiple employments
Starting or stopping self‑employment
Receiving additional income
Making (or not making) pension contributions
Receiving bonuses, commissions, or benefits
Starting side activities or online income
If something feels “minor” or “probably not taxable”, please still tell us. It is always safer to disclose and review than to leave something out.
I have included a list of things in the bottom of this blog.
HMRC Letters: Please Always Act on Them
One of the most important points we want to stress is this:
If you receive a letter, email, or message from HMRC, you must act on it and notify us immediately.
Even though we can log into your tax records through our own Government Gateway agent access:
We do not automatically see all HMRC letters or requests
Some letters are sent directly to you only
Some online messages do not generate agent notifications
Please do not assume we are aware of HMRC correspondence unless you have forwarded it to us.
Delays in responding to HMRC letters can result in:
Escalation of checks
Penalties for non‑response
Missed appeal deadlines
How We Can Help — and What We Need from You
We are here to support you and guide you through your tax obligations.
What we ask from you:
Provide complete and accurate information
Communicate changes and events during the year
Tell us your story — not just the figures
Inform us immediately of HMRC correspondence
Ask questions if you are unsure
If you realise a mistake has been made, letting us know as early as possible can reduce penalties and limit HMRC action.
Things Clients Commonly Forget to Tell Us
We get it — tax isn’t something you think about every day. But small details can make a big difference. Here’s a helpful checklist of things clients often forget to mention. If any of these apply to you, please tell us.
Changes in Your Job or Income
You changed jobs during the year
You had more than one job at the same time
You were made redundant or took time off work
You received a bonus, commission, or back pay
You did any freelance, contract, or “side” work (even if it felt small or informal)
You earned income online (Etsy, Vinted, Airbnb, tutoring, content creation, etc.)
Self‑Employment & Business Bits
You started or stopped being self‑employed
You paused trading for a while
You had a really good or really bad year
You took money out of the business that wasn’t wages or dividends
You paid for something personally that was actually for the business (or vice versa)
Pension & Savings
You were told your pension contributions increased — but didn’t actually check they were paid
You made a one‑off pension contribution personally
You transferred pensions or took money out of one
You received interest from savings accounts you don’t usually think about
Property & Renting
You started renting out a property or part of your home
You stopped renting a property
You let a property short‑term (Airbnb, holiday lets, etc.)
You sold a property or transferred it to someone else
Student Loans
Have student loans
Paid off student loans
Child Benefits
You received Child Benefits
Your partner received child benefits
Capital Gains (Very Commonly Missed)
Please always tell us if you:
Sold a property, shares, investments, or crypto
Gifted assets to someone (including family)
Sold business assets
Closed an investment account
Even if there was no cash profit — it can still matter for tax.
Life Events That Affect Tax
You moved house
You moved country (even temporarily)
You got married, divorced, or separated
You received an inheritance
You received large sums of money or gifts
If Something Feels “Probably Not Relevant…”
Please tell us anyway. Common things clients hesitate to mention:
“It was only a small amount”
“I didn’t think it counted”
“I wasn’t paid much”
“I thought HMRC wouldn’t care”
Those are exactly the things we should look at together.
Our job is to work out what matters and what doesn’t — but we can only do that if we know about it.
If in doubt, drop us a message. It’s always easier (and cheaper!) to deal with things upfront than later.
Final Thoughts
HMRC compliance checks are becoming more common and more detailed.
Our role is to advise, challenge where appropriate, and submit accurate returns — but we can only do that with the right information. If in doubt, please tell us. That conversation could save you years of stress later.