Getting your payment reference wrong is one of the most common Corporation Tax mistakes — and it can lead to HMRC chasing you for tax you've already paid. Here's exactly how to get it right.
What is a Corporation Tax payment reference?
Your Corporation Tax payment reference is a unique code you use when paying your Corporation Tax bill. It tells HMRC which company and which accounting period the payment is for.
If you use the wrong reference, HMRC can't match your payment to your return. You'll get automated reminders, then penalty notices, then interest charges — all while the money sits in HMRC's account, allocated to nobody.
How to construct your payment reference
Your Corporation Tax payment reference is made up of:
UTR + Period End Date
Format
[10-digit UTR][A][YY][MM]
Where:
- UTR = Your 10-digit Unique Taxpayer Reference
- A = The letter A (always)
- YY = Last 2 digits of the year your accounting period ends
- MM = 2-digit month your accounting period ends
Examples
| UTR | Period ending | Payment reference |
|---|---|---|
| 1234567890 | 31 March 2025 | 1234567890A2503 |
| 1234567890 | 31 December 2025 | 1234567890A2512 |
| 9876543210 | 30 June 2026 | 9876543210A2606 |
| 5555555555 | 31 January 2026 | 5555555555A2601 |
Important: Use the date your accounting period ends, not the date you're making the payment.
Where to find your UTR
Your Unique Taxpayer Reference is on:
- The letter HMRC sent when you registered for Corporation Tax
- Previous CT600 returns
- Your Government Gateway account (under 'Business tax account')
- Any correspondence from HMRC about Corporation Tax
If you've lost it, call HMRC on 0300 200 3410. They'll verify your identity and tell you your UTR.
How to pay Corporation Tax
Online banking (same day)
Transfer the payment to:
- Sort code: 08 32 10
- Account number: 12001039
- Account name: HMRC Cumbernauld
- Reference: Your payment reference (UTR + period end)
This is the fastest method — payment is usually processed the same day.
Direct Debit
Set up via your HMRC online account. Takes 3 working days to process. You need to set this up before your payment deadline.
CHAPS (same day)
Same bank details as online banking. CHAPS payments arrive the same day but your bank may charge a fee (typically £20-30).
Bacs (3 working days)
Same bank details. Allow 3 working days for the payment to reach HMRC.
Corporate credit/debit card
Pay through HMRC's online service. Credit card payments incur a fee. Debit cards are free.
At your bank or building society
Use payslip from HMRC's payment booklet. This is the slowest method — allow 3 working days.
Payment deadline
Corporation Tax must be paid by 9 months and 1 day after the end of your accounting period.
| Period ending | Payment deadline |
|---|---|
| 31 March 2025 | 1 January 2026 |
| 30 June 2025 | 1 April 2026 |
| 30 September 2025 | 1 July 2026 |
| 31 December 2025 | 1 October 2026 |
| 31 March 2026 | 1 January 2027 |
The payment deadline is different from the filing deadline. You can file your CT600 up to 12 months after the period end — but the tax must be paid earlier.
If your profit exceeds £1.5 million, you must make quarterly instalment payments. Most small companies don't need to worry about this.
What happens if you pay with the wrong reference?
If HMRC can't match your payment:
- Week 1-4: Payment sits in HMRC's suspense account
- Month 1: You receive an automated reminder that your tax is unpaid
- Month 6: Interest starts accruing (currently 7.5% per year)
- Month 6+: Potential late payment penalties
To fix it, call HMRC on 0300 200 3410 with:
- Your UTR
- The amount you paid
- The date you paid
- Your bank reference / transaction ID
- The correct accounting period
HMRC will reallocate the payment. Interest charges should be reversed once they confirm the payment was made on time.
What if you can't pay on time?
Contact HMRC before the deadline. They can arrange a Time to Pay agreement — a payment plan that lets you spread the bill over several months.
Call the Payment Support Service on 0300 200 3835. Have your UTR and details of your financial situation ready.
A Time to Pay agreement:
- Prevents further enforcement action
- Doesn't stop interest accruing (you'll still pay interest)
- Typically allows 6-12 months to pay
- Must be agreed before the deadline where possible
Common payment mistakes
1. Using the wrong period end date
Double-check your accounting period end date. If your accounts run to 31 March 2025, use A2503 — not A2603 (that's next year's return).
2. Confusing filing and payment deadlines
Filing deadline: 12 months after period end. Payment deadline: 9 months and 1 day after period end. The payment deadline comes first.
3. Paying from a personal account
Always pay from the company's bank account where possible. If you pay from a personal account, the reference is even more important — HMRC has no other way to identify the payment.
4. Rounding the payment
Pay the exact amount shown on your CT600. Don't round up or down — it can cause matching issues.
5. Missing the deadline by a day
HMRC's systems are automated. Even one day late triggers interest charges. Set a calendar reminder for 2 weeks before the deadline.
Taxpipe calculates your payment deadline
When you file your CT600 with Taxpipe, we show you:
- The exact amount of Corporation Tax owed
- Your payment deadline
- Your payment reference (UTR + period end)
- HMRC's bank details
Everything you need to make the payment correctly, in one place.
Related Articles
Related: how to pay Corporation Tax
