Corporation Tax · Northern Ireland
Corporation tax returns in Belfast
If your Belfast company has bought equipment, vehicles or software this year, made a loss, or has profits between £50,000 and £250,000, the Corporation Tax computation is where money is won or lost. We get the allowances, reliefs and marginal rate right, then file the return online for a fixed fee, serving all of Northern Ireland remotely.
from £199 · fixed, per return
Next deadlines
- Company tax return (CT600) due 12 months after your year end (a 31 December year end files by 31 December)
- R&D claim deadline: 2 years after the end of the accounting period (and the pre-notification window of 6 months after the period for first-time claimants)
- Companies House accounts due 9 months after your year end (a 31 December year end files by 30 September)
- Corporation Tax payment, 9 months and 1 day after your year end (a 31 December year end pays by 1 October)
Who this is for
Corporation Tax for Belfast
Limited companies in Belfast of every size below the large-company regime: companies whose accounts are prepared by another firm or in-house and need the tax return filed, companies with capital expenditure to claim, companies that have made a loss and want it used well, groups of associated companies, and companies whose CT600 is already overdue.
What is included
Everything inside the fixed fee
- Corporation Tax computation reconciling accounting profit to taxable profit, with every adjustment explained
- Capital allowances claimed in full: annual investment allowance, full expensing, writing-down allowances and the special rate pool
- Loss relief planned and claimed: carry back, carry forward and group relief where it applies
- Marginal relief and associated-company rules applied correctly between the 19% and 25% rates
- CT600 with supplementary pages, iXBRL-tagged accounts and computation, filed electronically with HMRC
- Payment note with amount, due date and HMRC reference, and reminders before the payment and filing dates
How it works
Corporation Tax from Belfast, step by step
Tell us your situation
A short message or call about what you do and what needs filing. We ask the questions that determine the right package and nothing more.
Fixed fee in writing
You receive one price for the work, confirmed by email before anything starts. It does not change if the job takes longer than we expected.
Send records, review the draft
Records come by WhatsApp or email. We prepare the draft, explain the figures in plain English and answer your questions.
We file, you get the receipts
Once you approve and the fee is settled, we submit electronically and forward the HMRC or Companies House acknowledgement the same day.
Why IGI
Why Belfast businesses file with IGI
No hourly rate and no surprise invoice. Belfast clients know the fee for corporation tax before they send a single document, and it stays fixed.
We work to the HMRC and Companies House calendar, not an appointment diary. Clients in Belfast get reminders at 60, 30 and 7 days before each date that applies to corporation tax.
We serve Belfast remotely by design: records by WhatsApp or email, drafts back for approval, filing electronic. The saving on premises is passed to you in the fee for corporation tax.
A named person handles your corporation tax from Belfast and knows the file, so you are not re-explaining your business to a different helpdesk each time.
Plain English, with the numbers. Every draft for Belfast comes with a short explanation of what the figures mean and what, if anything, you should do about them.
You stay in control of corporation tax: drafts go to Belfast clients first, with the figures explained, and nothing leaves us until you say so.
Local facts
About Belfast
Belfast is in Northern Ireland, in the BT1 postcode district, Northern Ireland. Northern Ireland uses the same income tax, National Insurance and Corporation Tax rates as Great Britain, and companies file with Companies House on the Belfast register. Stamp Duty Land Tax applies to property. For goods, the Windsor Framework means some EU VAT rules apply to trade with the EU, which affects businesses moving goods across the border.
| Place | Distance | Direction |
|---|---|---|
| Glengormley | 4 mi | N |
| Newtownabbey | 4 mi | N |
| Holywood, Northern Ireland | 5 mi | NE |
| Dundonald, Northern Ireland | 5 mi | E |
| Carryduff | 6 mi | S |
| Greenisland | 8 mi | N |
| Lisburn | 8 mi | SW |
| Comber, Northern Ireland | 8 mi | SE |
Worth knowing
Rules that come up in this work
Switching accountants
Changing accountant is simpler than most people fear. You authorise the new firm, which writes to the old one for professional clearance and your records; the outgoing accountant must hand over your own documents and usually does within two weeks. The new firm registers as your agent with HMRC and picks up the next filing. There is no need to wait for a year end.
Closing a company
Striking off a company is cheap but must be done in order: stop trading, file the final accounts and CT600, pay the tax, close VAT and PAYE, distribute the remaining assets, close the bank account, then apply. Anything left in the company at dissolution passes to the Crown. Distributions up to £25,000 are taxed as capital gains; above that a formal liquidation is usually needed to keep capital treatment.
Crypto records and reporting
Crypto tax splits into capital gains on disposals and income on rewards, with different rates and different reporting. The £3,000 annual exempt amount and the 18% and 24% rates apply to gains; staking, mining and airdrop income is taxed at marginal income tax rates. HMRC's nudge letters to holders have increased sharply, and a voluntary disclosure before one arrives is treated far more leniently.
The 60-day property CGT return
Since April 2020 a gain on UK residential property must be reported and the tax paid within 60 days of completion through HMRC's dedicated service, separately from the annual return. Non-residents must report all UK land disposals in the same window whether or not tax is due. Getting the computation right first time matters because the figure is then carried into the Self Assessment.
Record keeping
HMRC requires records of all income and expenses, bank statements, invoices and receipts to be kept for at least five years after the 31 January filing deadline of the tax year they relate to, and companies must keep records for six years from the end of the accounting period. Digital copies are acceptable. Under Making Tax Digital the records must be kept in compatible software.
Allowable expenses
Expense claims are where a return is won or lost in an enquiry. The test is wholly and exclusively for the trade; where a cost is mixed, the business proportion can be claimed if it can be identified. Capital items such as equipment and vans are relieved through capital allowances rather than as expenses, except under the cash basis where they are simply deducted when paid.
Employer National Insurance
The cost of an employee is more than the salary. Employer National Insurance at 15% above £5,000 a year, the 3% minimum pension contribution, holiday pay, equipment and management time all come on top. The Employment Allowance of £10,500 reduces the National Insurance for most employers with more than one person on the payroll.
Questions
Corporation Tax questions from Belfast
What are associated companies and why do they matter?
Companies under common control count as associated, and the £50,000 and £250,000 thresholds are divided between them. A director who owns two companies has thresholds of £25,000 and £125,000 for each. Missing this is a common error that produces an underpayment and interest.
When is Corporation Tax paid and the return filed?
Tax is due nine months and one day after the end of the accounting period; the CT600 is due twelve months after it. Companies with profits over £1.5 million pay by instalments instead. Interest runs on late payment from the due date, and a late return attracts a £100 penalty rising to 10% of the tax at twelve months.
What are capital allowances and what can I claim?
Capital allowances are the tax equivalent of depreciation. The annual investment allowance gives 100% relief on up to £1 million of qualifying plant and machinery a year; full expensing gives 100% on new main-rate assets without limit; cars and integral features go into pools at 18% or 6%. The £299 package reviews every asset purchase in the year.
Is the CT600 included when you prepare the accounts?
Yes. Our limited company accounts packages at £299 and £449 include the computation, the CT600 and filing with HMRC. The standalone fees on this page are for companies whose accounts are prepared elsewhere or where the return needs separate work such as a capital allowances review.
What are the Corporation Tax rates for 2026/27?
Profits up to £50,000 are taxed at the 19% small profits rate. Profits above £250,000 pay the 25% main rate. Between the two, marginal relief produces an effective rate rising from 19% towards 25%, with a marginal rate of 26.5% on each pound in the band. The thresholds are divided by the number of associated companies plus one.
What is iXBRL and do I need to worry about it?
HMRC requires the accounts and computation attached to a CT600 to be tagged in iXBRL, a machine-readable format. We produce and validate the tagged files as part of the service. If another firm prepared your accounts we tag their figures; you never deal with it directly.
Do you have an office in Belfast?
No. IGI Accounting is an online-only firm. We serve Belfast and every other UK postcode remotely, with records sent by WhatsApp or email and everything filed electronically. The absence of local premises is why the fee for corporation tax is the same in Belfast as anywhere else in the country, and why there is nothing to visit and nothing to print.
Is corporation tax in Belfast really the same price as elsewhere?
Yes. The fee published on this page is what a client in Belfast pays and what a client in any other part of Northern Ireland pays. It is confirmed in writing before work starts and the invoice matches the quote. Where a higher package applies because your situation is more complex, we say so at the quote stage, never afterwards.
Let us take the deadlines off your plate in Belfast
Tell us what you need. You get one fixed fee in writing, and nothing is filed until you approve it.