Corporation Tax Late-Filing Penalties Have Doubled: What Limited Companies Need to Know.

There is a timely reason for limited company directors to check their Corporation Tax position now.

HMRC confirmed in its Agent Update published on 20 August 2026 that automatic Corporation Tax late-filing penalty notices are being issued again.

HMRC temporarily paused the notices while it updated its systems to apply the new, higher penalty amounts correctly.

That update has now been completed.

Companies that filed late during the pause are still liable for the penalty, even if the notice arrives later than would normally be expected.

You can read HMRC’s August 2026 Agent Update for the latest announcement.

Corporation Tax has two different deadlines.

One of the easiest Corporation Tax mistakes is assuming that the tax payment and the Company Tax Return are due at the same time.

They usually are not.

For a company with taxable profits of up to £1.5 million, the normal deadlines are:

This means the tax itself is normally due before the deadline for filing the return.

Companies with taxable profits above £1.5 million may instead be required to pay Corporation Tax by instalments.

HMRC explains the main accounts and Corporation Tax deadlines for private limited companies , while its Corporation Tax payment guidance covers the rules for companies with larger taxable profits.

What are the new Corporation Tax late-filing penalties?

The fixed penalties doubled for Company Tax Returns with a filing date on or after 1 April 2026.

In practical terms, a company filing late for the first or second consecutive time now receives a £200 penalty as soon as the return is late.

If the return is still outstanding three months later, another £200 is added.

If the company has filed its return late three times in a row, those £200 penalties increase to £1,000 each.

HMRC’s current Company Tax Return penalty guidance sets out the penalties in full.

What happens if the Company Tax Return is six months late?

This is where the cost can become much more significant.

If a Company Tax Return remains outstanding for six months, HMRC can estimate the Corporation Tax it believes the company owes.

HMRC calls this a tax determination.

A further penalty of 10% of the unpaid Corporation Tax can also apply.

If the return remains outstanding for twelve months, another penalty of 10% of the unpaid Corporation Tax can apply.

HMRC states that you cannot appeal against the tax determination itself.

The company needs to submit the outstanding return, after which HMRC will recalculate the Corporation Tax, interest and penalties due.

What if your company has no Corporation Tax to pay?

A nil Corporation Tax bill does not automatically remove the requirement to file a Company Tax Return.

If HMRC has issued a notice to deliver a Company Tax Return, the company must normally submit the return even if:

• the company made a loss;
• there is no Corporation Tax to pay; or
• the final tax liability is £0.

The fixed late-filing penalties can therefore still apply even where no Corporation Tax is due.

HMRC confirms this in its Company Tax Return guidance .

What about dormant companies?

Dormant companies need particular care because the Corporation Tax and Companies House rules are not identical.

A company that has stopped trading and has no other income can normally tell HMRC that it is dormant for Corporation Tax.

Once HMRC accepts the company as dormant, it will not normally need to file another Company Tax Return unless HMRC issues a further notice to deliver one.

However, if the company has already received a notice to deliver a return for a particular period, HMRC says that return will still need to be filed.

Read HMRC’s guidance for companies dormant for Corporation Tax .

Your company’s first year can be different.

New company directors should also be careful not to assume that the first statutory accounts automatically create one matching Corporation Tax Return.

A Corporation Tax accounting period cannot normally be longer than 12 months.

If your first statutory accounts cover more than twelve months, the company may therefore need to file two Company Tax Returns to cover that first set of accounts.

That can also mean two Corporation Tax payment deadlines.

HMRC explains this in its guidance on a limited company’s first accounts and Company Tax Return .

Corporation Tax deadlines and Companies House deadlines are not the same.

This is another area where company directors can become confused.

Your annual accounts filed with Companies House and your Company Tax Return filed with HMRC are different obligations.

For a typical private limited company after its first year:

Filing one does not automatically mean you have satisfied the other deadline.

Companies House has its own late-filing penalties

For private limited companies, the current Companies House penalties for filing annual accounts late are:

Companies House also doubles the penalty where the company’s accounts are late in two consecutive years.

See the current Companies House late-filing penalties .

Filing late and paying Corporation Tax late are different problems.

The penalties discussed above relate to filing the Company Tax Return.

Paying the Corporation Tax itself late creates a separate issue.

HMRC charges late-payment interest on Corporation Tax that is paid after the payment deadline.

Interest generally runs from the day after the tax should have been paid until the date it is actually paid.

The interest rate is linked to the Bank of England base rate and can change, so the current rate should always be checked rather than relying on an old figure.

HMRC provides separate guidance on Corporation Tax interest charges and publishes current HMRC interest rates .

Can you appeal a Corporation Tax late-filing penalty?

Potentially.

HMRC allows a company to appeal a late-filing penalty where there is a reasonable excuse for missing the deadline.

What counts as reasonable depends on the circumstances.

Examples HMRC says may potentially amount to a reasonable excuse include:

• an unexpected stay in hospital;
• a serious or life-threatening illness;
• bereavement close to the deadline;
• computer or software failure while preparing the return;
• problems with HMRC’s online services;
• fire, flood or theft affecting records; or
• other circumstances genuinely preventing the obligation being met.

Each case is considered on its own facts.

For a Company Tax Return late-filing appeal, HMRC states that the outstanding return must be filed before the penalty is appealed.

Tax penalty appeals normally need to be made within 30 days of the penalty being issued. If you are outside that period, HMRC will normally require an explanation for the delay.

See HMRC’s guidance on reasonable excuses and appealing a Company Tax Return late-filing penalty .

Good records make meeting Corporation Tax deadlines much easier.

Filing problems often begin long before the actual deadline.

If bookkeeping is months behind, bank accounts are not reconciled, receipts are missing or directors have not dealt with questions from their accountant, preparing an accurate Company Tax Return becomes much harder.

HMRC requires companies to retain accounting records and supporting information used for Corporation Tax purposes.

In most cases, relevant company tax records need to be kept for at least six years from the end of the financial year they relate to, and sometimes longer.

This can include:

• sales invoices and records of money received;
• purchase invoices and receipts;
• bank statements;
• contracts;
• details of company assets;
• records of liabilities;
• stock records where relevant; and
• other information needed to support the figures in the accounts and Company Tax Return.

Read the Government’s company and accounting record guidance .

What should you do if your Company Tax Return is already late?

Ignoring it will not improve the position.

HMRC has specifically confirmed that businesses whose automatic penalty notices were delayed during its recent system update remain liable for the relevant penalties.

If the return is already overdue, the priority should normally be to establish what is outstanding and deal with it as quickly as possible.

1. Confirm which accounting period is overdue. Check the Company’s HMRC records and make sure you are working from the correct Corporation Tax accounting period and deadline.
2. Bring the accounting records up to date. Resolve missing information, unreconciled balances and unanswered accounting queries as quickly as possible.
3. File the outstanding Company Tax Return. Further penalties can arise while the return remains outstanding.
4. Check whether Corporation Tax is also unpaid. The payment deadline usually falls before the filing deadline, so late-payment interest may already be accruing.
5. Review any penalty notice carefully. Check the accounting period, filing date, amount and whether the higher repeated-failure penalties have been applied.
6. Consider whether there was a reasonable excuse. If there was a genuine reason that prevented filing on time, gather supporting evidence and consider whether an appeal is appropriate.
7. Check Companies House separately. Do not assume filing the Company Tax Return has dealt with the company’s annual accounts obligation.
8. Fix the process for next year. A penalty is frustrating. Repeated late filing is considerably more expensive, so identify what caused the delay and build the next deadline into the company’s financial timetable.

RiverView view: the deadline should not be the first time anyone looks at the numbers.

Filing a Company Tax Return is an annual compliance requirement.

But the information needed to complete it should be maintained throughout the year.

If a business only discovers that its bookkeeping is incomplete, its Corporation Tax bill is larger than expected or important information is missing shortly before the deadline, there is very little room left to respond.

Good financial management means knowing where the company stands before a statutory deadline forces the question.

RiverView Portfolio’s Business & Financial Strategy support is designed to help business owners use their financial information throughout the year rather than treating the accounts purely as an annual compliance exercise.

Our article Do You Put Yourself First When Looking at Your Numbers? also looks at why useful financial information should support decisions before the year has already passed.

Late Corporation Tax returns have become more expensive.

The doubling of the fixed penalties changes the cost of getting a Company Tax Return deadline wrong.

A return filed even one day late can now trigger a £200 penalty.

Leave it outstanding for more than three months and the fixed penalties can reach £400.

Repeat the problem for three consecutive returns and those fixed penalties can rise to £2,000.

At six and twelve months, penalties linked to unpaid Corporation Tax can make the position more serious again.

Add the separate Corporation Tax payment deadline, potential late-payment interest and Companies House filing obligations, and it becomes clear why relying on one date in the diary is not enough.

The simplest approach is to know which deadlines apply, keep the records needed to meet them and deal with problems before they turn into penalties.

Frequently asked questions.

This article provides general business and tax information only and does not constitute tax, legal or financial advice. Filing and payment requirements can vary according to a company’s circumstances, accounting period and level of taxable profits. Current HMRC and Companies House guidance should be checked where relevant.