What is included
- CT600 prepared and filed with HMRC
- 19%, marginal relief and 25% bands planned properly
- Capital allowances and AIA claimed
- Loss relief and carry back reviewed
- Payment deadlines tracked and diarised
- HMRC correspondence handled
Our services · Watford, Bushey & North West London
Your Corporation Tax computed properly, every relief claimed, and every deadline tracked so nothing slips.
Corporation Tax is charged at 19% on profits up to £50,000 and 25% on profits above £250,000, with marginal relief between the two creating an effective 26.5% rate on profits in that band. Tax is payable nine months and one day after your year end, and the CT600 return is due twelve months after year end.
Corporation Tax in 2026/27 runs at 19% on profits up to £50,000, 25% above £250,000, and an effective 26.5% marginal rate on the band in between. That middle band is where planning earns its keep, because timing, pension contributions and capital allowances genuinely change the bill.
We prepare and file your CT600, calculate the liability correctly, and make sure you claim what you are entitled to: capital allowances and the Annual Investment Allowance, loss relief and carry back, and R&D relief where it genuinely applies. We also track your payment deadline, nine months and one day after your year end, so the money is planned for rather than a surprise.
| Small profits rate | 19% up to £50,000 |
| Main rate | 25% above £250,000 |
| Effective marginal rate | 26.5% between £50,000 and £250,000 |
| CT payment deadline | 9 months and 1 day after year end |
| CT600 return deadline | 12 months after year end |
| Annual Investment Allowance | £1 million |
| Full expensing | 100% first-year relief on qualifying new plant and machinery |
| Loss carry-back | 1 year as standard |
| Overdrawn director's loan charge | 35.75% under section 455 |
| Section 455 repayment window | 9 months and 1 day after year end |
| Associated companies | Thresholds divided by the number of associated companies |
Profits between £50,000 and £250,000 are effectively taxed at 26.5%, which is higher than the headline 25% main rate. That band is where timing decisions genuinely change the bill: bringing forward equipment purchases, making an employer pension contribution before year end, or adjusting when work is invoiced.
A company sitting just above £50,000 has more room to act than one at £300,000, and the actions have to happen before the year end closes. That is why we review client positions two to three months out rather than at filing.
19% on profits up to £50,000 and 25% above £250,000. Between those figures marginal relief applies, producing an effective 26.5% rate on the slice in between. If you control other companies, those thresholds are divided between them, which frequently pushes owner-managed groups into a higher rate than expected.
Payment is due nine months and one day after your accounting year end. The CT600 return itself is due twelve months after year end. They are different dates and both carry penalties, so we diarise both for every client.
Employer pension contributions, timing of capital expenditure to use the Annual Investment Allowance or full expensing, correct treatment of losses, and reviewing whether costs currently treated as drawings are genuinely deductible. The planning conversation needs to happen before your year end, not after it.
Companies under common control are associated, and the £50,000 and £250,000 thresholds are divided by the number of associated companies. Two companies means the small profits limit falls to £25,000 each. Property owners with multiple SPVs are caught by this constantly.
If the balance is not repaid within nine months and one day of your year end, the company pays a section 455 charge of 35.75% of the outstanding amount. It is refundable once the loan is repaid, but the money is tied up with HMRC in the meantime and the reclaim is slow.
Yes. A trading loss can normally be carried back one year against total profits, generating a repayment of Corporation Tax already paid. Losses can also be carried forward against future profits. Which route is better depends on the rate applying in each period.
We provide corporation tax across Watford, Bushey, Harrow and North West London. Related services: Self Assessment Tax Returns · Bookkeeping and Making Tax Digital · VAT Returns and Registration · Payroll and PAYE · Company Accounts · CIS for Construction.
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