HMRC Corporation Tax Refund: How Long Does It Take?

You've overpaid your corporation tax and you're owed money back. The obvious question: how long will HMRC take to refund it?

The honest answer is that it depends — on how you filed, why you're owed money, and whether HMRC decides to check your return. This guide covers realistic timescales, what causes delays, and how to speed things up.

Standard Refund Timescales

HMRC's official target for processing corporation tax repayments is 40 working days (roughly 8 weeks) from receiving a valid claim.

In practice, timescales vary:

Scenario	Typical timescale
Simple overpayment (CT600 filed, tax already paid)	2–4 weeks
CT600 amendment creating a repayment	4–6 weeks
Loss carry-back claim	6–12 weeks
R&D tax credit claim	8–16 weeks
First CT600 for a new company	4–8 weeks
Claim during HMRC enquiry	Delayed until enquiry closes

These are estimates based on typical processing times. HMRC doesn't guarantee specific deadlines for repayments.

Why You Might Be Owed a Refund

Several situations create corporation tax overpayments:

You paid too much on account

If you estimated your corporation tax liability before filing your CT600 and paid more than the final amount due, the difference is a repayment.

Loss carry-back

If your company made a trading loss, you can carry it back to the previous accounting period and reclaim tax already paid. This is claimed on the CT600 for the loss-making period.

R&D tax credits

Companies claiming R&D tax relief can receive a payable tax credit, even if they have no corporation tax liability to offset it against.

CT600 amendment

If you filed your return and later realised you understated an expense or overclaimed income, an amendment can create a repayment.

Double payment

Sometimes companies accidentally pay twice — once via direct payment and once via direct debit. HMRC should identify this automatically, but it doesn't always happen quickly.

The Refund Process: Step by Step

Step 1: File your CT600

HMRC cannot process a repayment until your CT600 is filed. If you've paid tax but haven't submitted your return, the overpayment sits on your account but won't be refunded automatically.

Step 2: HMRC processes the return

Once filed, HMRC's systems process the return and calculate whether you're owed money. For straightforward returns filed electronically, this typically takes a few days.

Step 3: Security checks

HMRC runs automated checks on all repayment claims. These checks flag returns that:

Claim unusually large repayments relative to the company's history
Are from newly incorporated companies
Include R&D claims or other reliefs that are commonly abused
Show patterns that match known fraud indicators

If your return is flagged, it goes to a repayment review team for manual inspection. This is the most common cause of delays.

Step 4: Repayment issued

If everything checks out, HMRC issues the repayment. The method depends on your setup:

BACS transfer — if HMRC has your bank details (fastest method, 2–3 working days once issued)
Payable order (cheque) — if no bank details are on file (add postal time)
Offset against other liabilities — if you owe HMRC money for other taxes, they'll offset the refund against the debt first

How to Check Your Refund Status

HMRC online account

Log into your HMRC Business Tax Account and check the corporation tax section. It shows:

Your current balance (credit or debit)
Whether a repayment is being processed
When the last payment or repayment was made

Phone HMRC

Call the Corporation Tax helpline on 0300 200 3410 (Monday–Friday, 8am–6pm). You'll need:

Your company's UTR (Unique Taxpayer Reference)
The accounting period the refund relates to
Your company name and registration number

Be prepared for long hold times. HMRC's phone lines are notoriously busy, especially in January–March.

Agent access

If you have an accountant or tax agent, they can check via their agent services account. Agents often get through to HMRC faster via dedicated agent phone lines.

What Causes Delays?

1. Missing bank details

HMRC needs your company's bank details to make a BACS payment. If they're not on file, the repayment gets stuck.

Fix: Log into your HMRC Business Tax Account and add or update your bank details. You can also include them when filing your CT600.

2. Security review

HMRC's fraud prevention systems flag certain claims for manual review. Common triggers:

New companies claiming repayments on their first CT600
Large R&D claims relative to company turnover
Loss carry-back claims that generate substantial repayments
Unusual patterns — such as alternating between profits and losses

You can't prevent a security review, but you can reduce the chance by:

Ensuring your CT600 is accurate and complete
Including detailed computations with your return
Having supporting documentation ready if HMRC asks

3. Outstanding CT600s

If your company has unfiled CT600s for other periods, HMRC may withhold the repayment until they're submitted. They want to ensure the overall position is correct before releasing money.

Fix: File all outstanding returns before expecting a repayment.

4. HMRC enquiry

If HMRC opens an enquiry into your CT600, any repayment linked to that return is usually frozen until the enquiry concludes. Enquiries can take 6–18 months.

5. Incorrect filing

Errors in your CT600 — wrong accounting period dates, mismatched figures between the return and accounts, or incorrect claim boxes — can cause HMRC to reject the return or delay processing.

Fix: Double-check your return before filing. Common mistakes are covered in our CT600 errors guide.

6. Offset against other debts

If your company owes HMRC money for PAYE, VAT, or other taxes, HMRC will offset the corporation tax refund against those debts before releasing any balance. They'll write to you explaining the offset.

How to Speed Up Your Refund

File electronically

Paper CT600s take significantly longer to process. File online using approved software — HMRC processes electronic returns much faster.

Provide bank details upfront

Include your company bank details on the CT600 or ensure they're registered in your HMRC online account. This avoids the delay of HMRC writing to request them.

File accurate returns

Returns that don't need manual correction fly through the system. Use reliable CT600 filing software and check your figures against your accounts before submitting.

File all outstanding returns

Clear any backlog of unfiled CT600s. HMRC is much more likely to delay repayments when other periods are outstanding.

Keep records ready

If HMRC asks for supporting information, respond quickly and completely. Half the delay in repayment queries comes from slow responses to HMRC's questions.

Claim correctly

Make sure you've ticked the right boxes on the CT600. The repayment claim is in Box 95 — tick "yes" to request repayment of any overpaid tax. If you leave this unticked, HMRC may hold the credit on your account rather than refunding it.

Interest on Late Refunds

If HMRC takes too long to process your repayment, they owe you repayment interest.

Corporation tax repayment interest runs from the later of:

The date the tax was paid
The normal due date for the tax

The current repayment interest rate is set by HMRC and changes periodically. Check the HMRC interest rates page for the current rate.

Repayment interest is taxable — your company must include it as income in the next CT600.

R&D Tax Credit Refunds: Special Rules

R&D tax credit claims have additional processing steps:

Pre-notification — since April 2023, companies must notify HMRC of their intention to claim within 6 months of the end of the accounting period (for first-time or lapsed claimants)
Additional Information Form — all R&D claims must be accompanied by a detailed description of the R&D projects
Compliance checks — HMRC has significantly increased scrutiny of R&D claims since 2023

R&D refunds routinely take 3–4 months and can take longer if HMRC opens a compliance check. Claims above £50,000 are almost always reviewed manually.

What If Your Refund Is Taking Too Long?

If your refund has been pending for more than 40 working days and you haven't heard from HMRC:

Check your HMRC online account — confirm the return shows as received and processed
Call HMRC on 0300 200 3410 — ask specifically about the repayment status
Write to HMRC — Corporation Tax Services, HM Revenue & Customs, BX9 1AX
Complain formally — if HMRC has caused unreasonable delay, use their complaints procedure
Contact your MP — as a last resort, an MP can make enquiries on your behalf through the Parliamentary channel

If HMRC is holding your repayment pending a review, they should write to you explaining what information they need. Respond promptly — every day you delay is a day added to the refund timeline.

Avoiding Overpayments in the First Place

The best refund is one you never need to claim:

Calculate your liability accurately before the payment deadline using a corporation tax calculator
Don't overpay "just in case" — pay what you owe, no more
Check for marginal relief — many companies pay the 25% rate when they actually qualify for a lower effective rate
Review your allowable expenses — claiming everything you're entitled to reduces your liability and prevents overpayment

Frequently Asked Questions

Can I get my refund paid into a different bank account?

HMRC will only pay refunds into a bank account in the company's name. They won't pay into a director's personal account or a third-party account. Update your bank details via your HMRC Business Tax Account.

What if my company has been dissolved?

If the company has been struck off, claiming a refund becomes complicated. You may need to restore the company via Companies House to receive the refund. HMRC cannot pay refunds to dissolved companies.

Do I need to claim the refund or is it automatic?

If you file a CT600 showing that you've overpaid, HMRC should process the refund automatically — provided you've ticked Box 95 requesting repayment. However, it's good practice to follow up if you don't see the refund within 6 weeks.

Related: For step-by-step instructions on claiming a refund, see how to claim back overpaid corporation tax. If you overpaid by mistake, our corporation tax refund for overpayment guide covers the process.

Can HMRC refuse to refund my overpayment?

HMRC can withhold a repayment if they suspect the claim is incorrect, if you have outstanding tax debts, or if they've opened an enquiry. They must inform you if they're withholding payment and give you the opportunity to provide evidence.

Is the refund subject to tax?

The refund itself is not taxable — it's your own money coming back. However, any repayment interest HMRC pays is taxable as income of the company.

How long can I wait before claiming a refund?

You have 4 years from the end of the accounting period to amend your CT600 and claim a refund for overpaid corporation tax. After 4 years, you lose the right to claim.