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Late filing and late payment penalties — explained clearly, with no jargon.
If you’re searching “Self Assessment penalty”, you’re probably worried you’ve missed something — a deadline, a payment, or a letter from HMRC.
This guide explains:
– the late filing penalty ladder (including the £100 penalty and daily penalties)
– late payment penalties and interest
– what to do right now if you’re late
– when you can appeal (reasonable excuse)
– how to avoid it happening again
And if you’d rather have it handled properly, we can file your Self Assessment on a fixed fee — with fast answers in plain English.
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There are usually 3 penalty areas:
1) Late filing (return submitted after the deadline)
2) Late payment (tax unpaid after the payment deadline)
3) Registering late / telling HMRC late (failure to notify in some cases)
If you’re late right now, your best move is simple:
– file the return
– pay what you can
– act early on a payment plan if needed
– appeal only if you genuinely have a reasonable excuse (with dates and evidence)
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If you file your tax return late, HMRC penalties can include:
– an initial £100 penalty
– after 3 months: daily penalties of £10 per day (up to a maximum of £900)
– after 6 months: a further penalty of 5% of the tax due or £300 (whichever is greater)
– after 12 months: another 5% or £300 charge (whichever is greater)
Tip: Filing ASAP is the fastest way to stop penalties escalating.
If you pay your Self Assessment tax late, HMRC can charge penalties of 5% of the tax unpaid at:
– 30 days
– 6 months
– 12 months
Interest is also charged on the amount owed. Paying sooner reduces the damage.
If you register after 5 October and do not pay all of your tax bill by 31 January, you may get a “failure to notify” penalty in some cases.
This penalty is based on the amount still left to pay.
If you’re unsure whether this applies, we can confirm quickly.
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If you’ve missed a deadline or you’re worried you might:
1) File the return (even if you can’t pay in full yet)
This stops late filing penalties getting worse.
2) Pay what you can
This reduces interest and helps reduce late payment penalties.
3) If you can’t pay in full, act early
You may be able to arrange a payment plan (Time to Pay) depending on your situation.
4) Only appeal if you have a genuine “reasonable excuse”
Appeals work best when you have clear evidence, dates, and you acted as soon as you were able.
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If you want it calm, accurate, and planned properly, we’ll handle your Self Assessment return and help you understand payments on account clearly — with fixed fees and fast answers in plain English.
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If you have a reasonable excuse, you can appeal against a Self Assessment penalty.
A “reasonable excuse” is something that genuinely stopped you meeting your tax obligation for a valid reason — and you must send the return or payment as soon as you’re able to.
Examples that may count (depending on your situation):
– a close relative died shortly before the deadline
– an unexpected hospital stay prevented you dealing with your tax affairs
– serious or life-threatening illness
– your computer/software failed while preparing your online return
– issues with HMRC online services
– fire, flood or theft
– unexpected postal delays
– delays related to a disability or mental illness
– you were unaware of or misunderstood your legal obligation
– you relied on someone else to send your return and they did not
Examples that will not count:
– you did not have enough money (payment failed)
– you found HMRC online services too difficult to use
– you did not get a reminder from HMRC
– you made a mistake on your tax return
Important: you usually have 30 days from the date your penalty was issued to contact HMRC or make an appeal.
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If you can’t pay in full, you may be able to set up a payment plan to pay in instalments.
To set up a payment plan, you’ll normally need:
– your reference number (for example your UTR)
– UK bank account details (for Direct Debit)
– details of your income and spending
If your bill is not overdue and you want to pay towards your next bill weekly or monthly, you may be able to use a Budget Payment Plan instead.
– waiting until late January to gather paperwork
– filing late even when you owe no tax (penalty can still apply)
– forgetting the 31 July payment on account (if applicable)
– ignoring HMRC letters instead of acting early
– reducing payments on account too aggressively (then being short later)
– not registering on time if it’s your first year filing
If you want a quick estimate of what penalties might apply, HMRC provides an online penalty estimate tool.
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Late filing penalties can start with an initial £100 penalty, and further penalties can apply if the return remains late.
A late filing penalty can still apply even if there is no tax to pay — so it’s worth filing as soon as possible.
HMRC can charge late payment penalties of 5% of the tax unpaid at 30 days, 6 months, and 12 months. Interest is also charged on the amount owed.
Yes. Filing the return stops late filing penalties getting worse. Then pay what you can and act early on a payment plan if needed.
Yes, if you have a reasonable excuse and you acted as soon as you were able to. You usually have 30 days from the date the penalty was issued to appeal.
Examples can include serious illness, bereavement, unexpected hospital stays, fire/flood/theft, HMRC online issues, or unexpected postal delays. You must file or pay as soon as you’re able.
You may be able to set up a payment plan (Time to Pay) to pay in instalments. It’s best to act early rather than ignore it.
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