Appeal a CIS late filing penalty

The 30 days start on the date printed on the penalty notice, not the day it reached you. Each penalty is assessed separately, so a return that stayed late can bring several notices. Appeal each one you disagree with.

While your appeal is open, you don't have to pay that penalty. If you don't appeal, it is due within 30 days of the notice.

File the late return now if you haven't. An excuse only counts if you filed without unreasonable delay once it ended. Each later penalty is only charged while the return is still missing.

A reasonable excuse is something that stopped you filing for a good reason. GOV.UK gives these examples:

• your partner or a close relative died shortly before the deadline
• an unexpected stay in hospital
• a serious or life-threatening illness
• your computer or software failed while you were preparing the return
• a problem with HMRC's online services
• a fire, flood or theft stopped you
• postal delays you could not have predicted
• delays from a disability or mental illness
• you didn't know about, or misunderstood, what you had to do
• you relied on someone else to send the return, and they didn't

These will not be accepted:

• a payment failed because you didn't have enough money
• you found HMRC's online system too hard to use
• you didn't get a reminder from HMRC
• you made a mistake on your return

The law adds two limits. Not having the money only counts if it came from events outside your control. Relying on a bookkeeper or accountant who didn't file only counts if you took reasonable care to make sure it was done.

1. Online, through HMRC's CIS online service. You sign in with your Government Gateway login, and you can track the appeal there.
2. In writing, to the CIS address on GOV.UK's HMRC contacts page. Sign the letter and quote your Unique Taxpayer Reference (UTR) and the payment reference on the notice. If the notice came with an appeal form, you can use that.

You cannot appeal over the phone.

You can appeal because you had a reasonable excuse, or because the penalty itself is wrong. For example, the return was filed on time, or the amount is not what the law allows.

Keep it short and stick to facts and dates. Include:

• your name or business name, your UTR and the payment reference on the notice
• the tax month the return was for, for example 6 May to 5 June
• the date the return was due and the date you filed it
• what stopped you filing, and when it started and ended
• your evidence, such as hospital dates, or the date you tried to file and the error message you got
• what you are asking for: the penalty cancelled, or reduced

Keep a copy of what you send, and a note of the date you sent it.

If HMRC won't change its decision, it will offer a review by an officer who wasn't involved. Reviews usually take 45 days. The officer can keep the penalty, change it or cancel it.

You can also take the appeal to the tax tribunal, which can confirm, change or cancel the penalty. After a review, you usually have 30 days from the date on the review letter to go to the tribunal.

Separately, HMRC can reduce a penalty if there are special circumstances. Not being able to afford it is not one.

You can still appeal late. Write to HMRC asking it to accept a late appeal, and give your reason for missing the 30 days. HMRC must agree if you had a reasonable excuse for the delay and asked as soon as it ended. If HMRC refuses, you can ask the tax tribunal for permission.

Since 6 April 2026, a month with no subbies paid needs a nil return by the 19th. The exception is when you told HMRC at least 14 days before the month started. A late nil return gets the same penalties as any other late return.

From 6 April 2015 to 5 April 2026, no nil return was needed. If you were fined for a month in that time when you paid no subbies, HMRC's own manual says an appeal telling it so will be accepted.

If you didn't know nil returns were back, GOV.UK lists not knowing what you had to do as something that may count. File the missing nil returns as soon as you find out, then appeal. CIS changes from 6 April 2026 explains what changed, and CIS nil returns covers how to tell HMRC in advance.

Some businesses are in CIS only because they spend over £3 million a year on construction. For them, HMRC's guide says a nil return is not required. If you file nothing, HMRC still sends a penalty. It says it will cancel it once you tell it no subbies were paid that month.

You can appeal a single penalty yourself. Get help if:

• HMRC says you held a return back on purpose, which can mean 70% or 100% of the deductions
• several months or several penalties are involved
• HMRC has refused and you are thinking about the tribunal
• you are not sure whether your reason counts

To see what a late return costs and when each penalty is charged, use the CIS penalty calculator. The full list of amounts is in CIS late filing penalties.