Corporation Tax · M25 Fringe
Corporation tax returns in Old Windsor
Corporation Tax for Old Windsor companies whose accounts are prepared elsewhere, or who want a second pair of eyes on the computation before HMRC sees it. We reconcile the accounting profit to the taxable figure, apply the correct rate, and file the CT600 with iXBRL accounts attached. One fixed fee per return, no hourly billing, nothing filed until you approve.
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 Old Windsor
Limited companies in Old Windsor 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 Old Windsor, step by step
Scope the job
We find out what you need filed, when it is due and what state the records are in, and tell you which fixed-fee package applies.
Agree the price
The fee is confirmed in writing. There is no hourly billing and nothing added for questions during the work.
Hand over the records
Photographs, PDFs, software access or a spreadsheet, sent however suits you. We confirm what we have and what is missing within two working days.
Approve, then we submit
You review the draft with our explanation, sign off, and we file. Receipts, copies and the next deadlines come back to you immediately.
Why IGI
What you get in Old Windsor
The price for corporation tax is published on this page and is what a client in Old Windsor pays. We confirm it in writing first, and the invoice matches the quote.
Nothing for Old Windsor is left to the last week. Each deadline relevant to corporation tax is tracked from the day you join, with the next four shown on every page we send you.
Online only, UK based. There is no office in Old Windsor to pay for, which is why the fee is the same here as anywhere in England; the work is done by people in the UK who answer the same day.
You get one contact for corporation tax, not a queue. Old Windsor clients message the same person throughout and get an answer in working hours, usually within a few hours.
The output for Old Windsor clients is never just a form. It is the form, a one-page summary of what it says, and a note of the decisions it points to for corporation tax.
Nothing is filed for Old Windsor until you have reviewed and approved it. You see the draft, you ask questions, you sign off, then we submit and send you the receipt.
Local facts
About Old Windsor
Old Windsor is in M25 Fringe, in the SL4 postcode district, England. For businesses in England the tax rules are those set by the UK Parliament: the 20/40/45% income tax bands, Class 4 National Insurance for the self-employed at 6% and 2%, Corporation Tax at 19% to 25%, and Stamp Duty Land Tax on property. Business rates are set locally by the council.
| Place | Distance | Direction |
|---|---|---|
| Friary Island | 0.3 mi | E |
| Woodside, Windsor and Maidenhead | 0.7 mi | SW |
| Wraysbury | 0.9 mi | E |
| Ham Fields | 1.0 mi | NE |
| Ham Island | 1.0 mi | NE |
| Green, The, Windsor and Maidenhead | 1 mi | E |
| The Green, Windsor and Maidenhead | 1 mi | E |
| Shaw Farm | 1 mi | NW |
Worth knowing
Rules that come up in this work
CIS deductions
The Construction Industry Scheme affects both sides of a construction payment. Contractors must verify subcontractors, deduct the right amount, issue statements and file monthly, with penalties from £100 for each late return. Subcontractors suffer deductions on turnover and recover the excess at the year end. Limited company subcontractors offset deductions against PAYE monthly instead.
Confirmation statements and identity verification
Companies House has tightened its requirements under the Economic Crime and Corporate Transparency Act: every company needs a registered email address and an appropriate registered office, every statement includes a lawful-purpose declaration, and every director and PSC must verify their identity. The confirmation statement, due annually with a £50 fee, is where most of this is confirmed.
Making Tax Digital for Income Tax
MTD for Income Tax replaces one annual return with quarterly digital updates and a year-end declaration, submitted from software. The threshold is gross trading and property income, measured two years earlier, and started at £50,000 in April 2026 before falling to £30,000 in April 2027. Anyone affected needs digital record keeping in place before their start date, not after.
Late filing penalties
Penalties are the clearest reason to work to deadlines. A Self Assessment return one day late costs £100 regardless of whether any tax is due; three months late adds £10 a day. Late company accounts start at £150 and reach £1,500, and double if the previous year was also late. None of this is negotiable afterwards except through a narrow reasonable-excuse appeal.
Payments on account
Payments on account catch out most people in their second year of self-employment. HMRC assumes next year's tax will match this year's and collects half in January and half in July, in advance, on top of the balancing payment. If profits are dropping you can apply to reduce them, but reducing them too far attracts interest. We calculate the right figure rather than guessing.
The Self Assessment calendar
Self Assessment runs on a fixed annual cycle. Registration by 5 October following the tax year, online filing and payment by 31 January, and a second instalment on 31 July for those making payments on account. The penalties for lateness are automatic and escalate monthly, which is why we file early and chase approvals well before the window closes.
Director's loan accounts
The most common tax problem in owner-managed companies is an overdrawn director's loan account: drawings taken during the year that were never declared as dividends or salary. The company faces a 35.75% charge on the balance outstanding nine months after the year end, and the director may have a benefit in kind. We review the account before every year end to clear it properly.
Questions
Corporation Tax questions from Old Windsor
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.
My company made a loss. What can be done with it?
A trading loss can be set against the company's other profits of the same year, carried back one year for a repayment of tax already paid, or carried forward against future profits. The right choice depends on cash flow and expected profits. We model the options and make the claim on the return.
What expenses are not allowed for Corporation Tax?
Business entertainment of customers, most fines and penalties, depreciation (replaced by capital allowances), general provisions, and the private element of mixed-use costs. Legal fees on capital items are also disallowed. The computation adds these back to accounting profit and we list every adjustment so you can see the effect.
Are dividends and salary treated differently for Corporation Tax?
Yes. Salary, employer National Insurance and employer pension contributions are deductible expenses that reduce taxable profit. Dividends are paid from profit after tax and are not deductible. This asymmetry is central to the salary-versus-dividend planning we do for directors.
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.
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.
Is corporation tax in Old Windsor really the same price as elsewhere?
Yes. The fee published on this page is what a client in Old Windsor pays and what a client in any other part of England 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.
Do you have an office in Old Windsor?
No. IGI Accounting is an online-only firm. We serve Old Windsor 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 Old Windsor as anywhere else in the country, and why there is nothing to visit and nothing to print.
Fixed fees, filed on time, for Old Windsor
Tell us what you need. You get one fixed fee in writing, and nothing is filed until you approve it.