R&D tax credit claims in Mansion House

Limited companies in Mansion House that have tried to achieve an advance in science or technology and faced genuine uncertainty doing it: software firms building something that did not exist, manufacturers developing new processes or materials, engineering businesses solving problems off the standard path, and food, biotech and clean-tech companies with development spend to recover.

• Eligibility review against the statutory definition of R&D for tax purposes, with a written yes or no
• Advance notification to HMRC within six months of the period end for first-time and lapsed claimants
• Technical narrative for each project: the scientific or technological uncertainty, the advance sought and how it was resolved
• Qualifying expenditure computed: staff costs, subcontractors, externally provided workers, software, consumables and data
• The Additional Information Form completed and submitted before the CT600 is filed
• Claim entered on the CT600 and the relief or payable credit tracked through to HMRC's payment

1. 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.

2. 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.

3. 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.

4. 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.

Mansion House is in Central London, within City of London, in the EC4V postcode district, England. Income tax in England follows the UK rates: 20% basic to £50,270, 40% higher to £125,140 and 45% additional, with the personal allowance of £12,570 tapered away above £100,000. National Insurance, VAT and Corporation Tax are UK-wide, and Stamp Duty Land Tax applies to property purchases.

Confirmation statements and identity verification

The confirmation statement is the annual check that the public register is right: officers, registered office, SIC codes, shareholders and the PSC register. It carries a £50 fee and no financial penalty for lateness, but failure to file leads to compulsory strike-off. The identity verification regime introduced in November 2025 has added a further check to every statement.

CIS deductions

Under the Construction Industry Scheme, contractors deduct 20% from a registered subcontractor's labour invoices, or 30% if unregistered, and pay it to HMRC. The subcontractor reclaims the deductions against their actual tax through Self Assessment, usually producing a refund because deductions are on turnover while tax is on profit. Contractors file a monthly return by the 19th.

Salary versus dividends

Directors of their own companies usually take a salary at or just above the National Insurance thresholds, which keeps the year qualifying for State Pension and is deductible for Corporation Tax, with further income as dividends. Dividends above the £500 allowance are taxed at 10.75%, 35.75% and 39.35% by band and can only be paid from distributable profits after tax, with a minute and voucher each time.

Director's loan accounts

Money taken from a company has to be something: salary, dividend, expense reimbursement or loan. If it is a loan and remains outstanding nine months after the year end, the company pays tax at the dividend higher rate on it until it is repaid. Clearing the balance with a properly declared dividend before the deadline, where reserves allow, is routine year-end work.

The VAT registration threshold

The £90,000 VAT threshold is measured over any twelve consecutive months, which is why a strong quarter can tip a business over unexpectedly. Registration must follow within thirty days of the end of the month the threshold was crossed. Below the threshold, voluntary registration is worth considering when customers are VAT-registered businesses and costs carry VAT.

Corporation Tax rates and marginal relief

Companies pay Corporation Tax at 19% on profits up to £50,000 and 25% on profits over £250,000. Between those figures marginal relief applies, producing an effective rate that rises gradually and a marginal rate of 26.5% on each pound in the band. The thresholds are divided by the number of associated companies, so a director with two companies has thresholds of £25,000 and £125,000 for each.

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.