Swift Accountants · You have someone to ask
A Self Assessment penalty notice can turn an ordinary day into a worrying one. We help you understand the letter, check what is outstanding and decide what needs attention first.
You may have missed a date, misunderstood a request or had something much more important happening in your life. Start by telling us what happened. You do not need every answer before asking for help.
No obligation to join. Clear scope and fees before work begins.
Make the situation smaller
Put the notice beside you and work through one question at a time. The aim is to understand the position and protect your next opportunity to act.
Find the tax year, issue date, amount and reason. Keep every page. A filing charge, a payment charge and an HMRC estimate of tax are different things.
Was it submitted and accepted? Gather the confirmation. If it is outstanding, identify the records needed. If you believe no return was required, raise that with HMRC.
Compare the tax account with bank evidence. Note the payment date, reference and amount. If money is tight, make that part of the conversation from the start.
The usual appeal window is 30 days from issue. Note the date now. Tell us immediately if it is close or has passed, so the available route can be checked.
A useful first message is: “I have a penalty for [tax year], dated [date]. My return is [filed/not filed/unsure], and I am worried about [the charge, payment or appeal].” We can then agree what to review and how to share it securely.
Understand what the charge relates to
These are the usual late-filing charges outside the newer MTD penalty system. They build on one another. Check the filing date on your notice rather than assuming every return had the same deadline.
| How late? | Additional charge | What it means |
|---|---|---|
| Deadline missed | £100 | The initial fixed filing penalty. |
| After 3 months | £10 a day, up to £900 | Daily charges can be added for up to 90 days. |
| After 6 months | £300 or 5% of the tax due, whichever is higher | A further charge on top of the earlier penalties. |
| After 12 months | Another £300 or 5%, whichever is higher | A further charge; the tax-based amount can exceed the minimum. |
Where the full daily charge and both £300 minimum charges apply, the calculation is £100 + £900 + £300 + £300 = £1,600. This is an illustration of filing penalties, not a calculation of your bill. Tax, interest and payment penalties are separate.
Source: HMRC’s Self Assessment penalty guidance. For the newer system, see the MTD section below.
A common and understandable question
A low income, a loss or an expected refund does not automatically remove a return that HMRC requires. The usual fixed filing penalty can apply even when the tax bill is nil or was paid on time.
Perhaps you stopped trading, changed jobs or no longer receive rent. Those changes matter, but HMRC still needs to confirm whether a return is required for the year concerned.
If you believe the return was unnecessary, use HMRC’s process to ask it to withdraw the requirement and consider cancelling the associated penalty. Keep the confirmation; do not assume that closing a business also closed your Self Assessment record.
We can help you separate the year you stopped from any final income, outstanding return or other reporting requirement. Start with our “Do I need a tax return?” checklist.
Tell HMRC a return is no longer needed · HMRC explains penalties where no tax is due.
A payment problem needs a realistic plan
Submitting the return and paying the bill are separate responsibilities. If the return is ready, waiting until you can afford the tax can create another problem alongside the one you already have.
Under the usual rules, overdue balancing tax can attract 5% charges at 30 days, six months and twelve months, based on the amount still unpaid at each point. Interest is a separate charge.
Payments on account are not themselves subject to this penalty in the same way. However, amounts still outstanding when the balancing payment falls due can enter the calculation. Late-payment interest can still apply.
We can help you understand the account, check payments already made and prepare a clear picture of what you can realistically afford.
Identify the original tax, interest and each penalty. An account balance can contain several charges; paying one does not necessarily clear the others.
HMRC may agree monthly instalments. You will need an honest picture of income, essential spending, savings and other commitments. Eligibility and approval depend on the circumstances.
An acceptable payment arrangement agreed by a relevant penalty trigger date can protect against further penalties during the arrangement if its terms are met. Interest normally continues.
You do not need to promise a monthly payment you cannot sustain. We can discuss the information HMRC will need; HMRC decides whether to accept a proposal. Read our payments on account guide if January and July bills are part of the confusion.
Official guidance: which payments attract penalties · payment plans · arrangements and penalty trigger dates.
An appeal starts with the facts
You can challenge a penalty you believe is wrong, or explain a reasonable excuse for the delay. For example, you may have evidence that HMRC received the return on time, or that a serious event prevented you dealing with it.
The usual deadline is 30 days from the date the penalty was issued. A late appeal needs an explanation for the delay as well. Check the notice and raise any approaching deadline straight away.
HMRC’s appeal service directs you to the appropriate online or postal route. For individuals, the postal form is normally SA370; partnerships have a different form.
We can review the notice, help organise the evidence and discuss whether an appeal is appropriate before agreeing the work. HMRC decides the outcome.
Keep the complete notice and specify the tax year, charge and amount you dispute. If several notices arrived together, make a simple list so none gets lost.
Write down what happened, when it started, how it affected the obligation and what you did afterwards. Clear dates are more useful than a long, general apology.
Match the explanation to relevant documents, messages or submission records. Retain a copy of the appeal and proof it was sent. We can help you organise what matters.
“I disagree with the penalty dated [date] for [tax year/type of charge] because [the specific reason]. The relevant events were [dates and facts]. I took action on [date]. My supporting evidence is [list]. I ask HMRC to review the penalty in light of these circumstances.”
Use your actual circumstances and the correct appeal route. Include the identification the form requests. This structure helps organise an explanation; it does not establish grounds for cancellation.
HMRC’s Self Assessment appeal service · Appeal deadlines and options.
When life has made things difficult
Explain what prevented compliance and how you responded. A relevant circumstance does not automatically cancel a penalty.
A serious illness, unexpected hospital stay, bereavement, or the effects of a disability or mental illness may be relevant. Explain the timing and practical impact.
Examples include a fire, flood, theft, unexpected postal disruption or an HMRC service failure. Keep relevant dates and evidence of attempts to comply.
HMRC’s guidance includes some cases involving misunderstood obligations or reliance on another person. These need careful consideration of your particular circumstances.
A missing reminder, difficulty using the website or insufficient funds causing a failed payment will not normally establish a reasonable excuse on their own.
You are more than a missed date
Sometimes the hardest part is admitting that the letters have been sitting unopened. Sometimes you have tried to sort everything and still cannot make sense of the account. Either way, you can tell us where you are.
We begin with the year, the notice and your main concern. Then we explain the work needed, the records to gather and what can realistically happen next. If a deadline is close, we will be clear about availability and the time required.
You should understand whether we are preparing a return, reviewing a penalty, helping with an appeal or explaining payment options. Each part deserves a clear scope, an agreed fee and someone you can ask when something is unclear.
A free first conversation, with no obligation to become a client.
Start with the notice, relevant tax year and any filing or payment evidence. We will agree a manageable checklist for the work, including any missing income records.
Ask questions by phone, keep an explanation by email or talk through the detail on a video call. We agree communication arrangements as part of your service.
We explain the scope, fee and any VAT before work starts. Earlier returns, bookkeeping, complex disputes or additional appeal work may need a separate quote.
Read the reason, not just the amount
The wording on the letter helps us identify the right problem to solve. Share the whole notice through the agreed secure process.
Registering after 5 October can lead to a failure-to-notify penalty where tax remains unpaid by the relevant January payment deadline. The amount depends on the circumstances; it is not simply another fixed £100 charge.
A notice about inaccurate information needs a different review from one about a late return. Tell us what HMRC says is wrong and provide the calculation and correspondence so the appropriate response can be considered.
A tax determination is not the same as a penalty. It needs checking alongside the missing return and any time limits. If a letter mentions a determination or assessment, flag that at the start of your enquiry.
Official guidance: late registration · tax determinations. We will explain whether the matter fits the work we can undertake or needs specialist support.
Making Tax Digital for Income Tax
For people required to join MTD from April 2026, the new system applies from 2026/27. Their 2025/26 return, normally due on 31 January 2027, remains under the previous rules.
Under the new submission system, missed deadlines can build penalty points. Four points trigger a £200 charge, with further £200 charges for subsequent missed submissions while at the threshold.
There are no late quarterly-update penalties for 2026/27. Digital records and the updates are still required. This concession does not remove every annual-return or payment obligation.
MTD also has different late-payment rules, including first-year provisions. Volunteers have separate guidance. Check your tax year and start date before applying a penalty table.
We can discuss a records routine that fits your business. Our Self Assessment deadlines guide helps you keep the dates together.
Get through this, then make next year easier
Once the immediate issue is understood, we can help you build a preparation routine around work, family and the way you manage money. Small, agreed actions are easier to maintain than a last-minute rush.
Know who gathers the records, prepares the return, checks the figures and makes the payment. Keep those responsibilities clear from the start.
Leave room to replace a missing statement, explain an unusual transaction and review the draft. Your preparation date should allow time before filing.
Save submission confirmations, payment receipts and important HMRC messages in the agreed secure place. They are easier to find when a question arrives.
Tell us about new income, stopping a business or changes to digital reporting. We can check what this means for the support and timetable you need.
We can discuss a straightforward handover with your permission and explain any outstanding work before you decide. The priority is understanding the current position and agreeing the next step. Explore our Self Assessment tax return service.
In our clients’ words
Short extracts from reviews published on our client page. Each reflects an individual experience; the outcome of a penalty matter depends on its facts and HMRC’s decision.
“got me a refund for penalty for late tax return” Patryk Lewandowski
“Really easy to get hold of” Claire Allwood
“kept in touch with me” Sharon Parry
The questions behind the worry
If the letter in front of you does not fit a general answer, tell us what is different. The detail can change the right next step.
Under the usual non-MTD filing rules, missing the deadline can trigger the initial fixed charge. There is no general one-day allowance. Check whether the deadline and recorded submission date are correct.
Do not assume a first late return brings an automatic waiver. Check whether the penalty is correct and whether there are grounds to challenge it. Explain what happened and retain the evidence.
Yes, a refund position does not itself remove a required return or the usual filing penalty. If the issue is that no return should have been required, ask HMRC to review that requirement.
Compare the tax year on the notice with the submitted return. Find the acceptance confirmation and check the reference used. Share those details so the recorded position can be investigated; a saved draft is different from an accepted submission.
The charge may concern filing, an earlier period, interest or a payment recorded elsewhere. Match the notice to your tax account and bank evidence, including the reference. We can help you identify what needs checking.
Keep the return moving while dealing with affordability separately. Waiting can leave both issues unresolved. Contact HMRC about payment options and tell us what records are ready so we can discuss the filing work.
A late appeal needs an explanation for its lateness. Gather the issue date, when you became aware of the notice and why you could not act sooner. Ask for advice promptly; acceptance of a late appeal is not automatic.
HMRC says a penalty under appeal need not be paid until the appeal is settled. However, interest can be payable if the appeal fails; HMRC suggests considering payment. The underlying tax is separate. Check HMRC’s payment-during-appeal guidance.
Read the reasons and the next deadline carefully. You may be able to request an HMRC review or appeal to the tax tribunal. Those routes have their own requirements; ask promptly about the options and likely work involved.
They may. Explain how the circumstances affected your ability to meet the obligation and what you did when able to act. You can tell us sensitively what support would make the conversation and document gathering easier.
Gather the engagement terms, records you supplied, messages and any filing confirmation. Reliance on another person needs a fact-specific review. We can discuss both the outstanding return and the explanation you may wish to give HMRC.
A missing reminder is not normally a reasonable excuse on its own. If something else prevented compliance, explain that fully and provide the relevant dates. Also check whether the return was actually required.
Make a list of the years, notices and records available. Each year may need separate work. We can assess the position, identify urgent dates and quote for the preparation and review needed before agreeing a timetable.
No. We can assess the facts, explain the available route and help present the position clearly. HMRC determines the outcome. You should understand the proposed work and its cost before deciding to proceed.
Appointing an accountant does not itself change an HMRC deadline. Tell us about urgent dates immediately. We need to assess the records, authority and time required before accepting time-sensitive work.
Yes. Start with the free chat. We will listen, identify the main issue and explain the service we can offer. You can ask about fees, communication and the documents needed, with no obligation to join.
Tell us the tax year, notice date, type of charge and your main concern. We will agree a secure way to receive documents if needed. Keep HMRC passwords out of messages; we arrange the appropriate authorisation for any agreed work.
Keep the next useful answer close
Understand our service and how we can agree the work.
Self Assessment support →Keep registration, filing and payment dates separate.
Explore the deadlines →Start with the income and circumstances that matter.
Read the checklist →Make sense of the amounts due in January and July.
Payments on account →For the life beyond the letter
You have people to look after, work to get on with and a life beyond this notice. Let us help you understand what needs doing, so the next step feels clearer.
You can begin with one question. We will meet you there.
Completely free first conversation. No obligation to join.
Listening,
Understanding,
Advising
Tell us what you need help with. We’ll call you to understand your situation, explain how we can help and agree the next steps.
