Business tax returns, calculated & optimised

From your Corporation Tax return to partnership filings and capital gains, we calculate, optimise and submit every business return well before the deadline — claiming every relief you're entitled to.

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Returns we handle

Corporation Tax (CT600)
Partnership returns (SA800)
Capital Gains & dividend reporting
MTD for Income Tax (from April 2026)
Personal Self Assessment for directors & partners

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Planning, not just compliance

We don't just file — we look for savings

Anyone can submit a return. We go further: reviewing reliefs, timing and structure so your business pays the right amount and not a penny more, with no nasty surprises at the deadline.

Proactive tax planning ahead of year end
Capital allowances & R&D opportunities flagged
Free representation if HMRC ever opens an enquiry

Why IGI

Confident, compliant, optimised

Every relief reviewed

We work through the allowances and reliefs that apply to your business so nothing is left on the table.

Filed before the deadline

We prepare returns early and submit on time, every time, so you avoid interest and penalties.

HMRC cover included

If HMRC ever investigates, we handle the correspondence and represent you — at no extra cost.

Good to know

Tax return FAQs

For most companies, corporation tax is payable nine months and one day after the end of your accounting period, and the CT600 return is due within 12 months. We calculate and file early so you know the figure with time to plan.

Yes — we prepare the partnership return (SA800), the partnership accounts and each partner's personal Self Assessment, with profit-share calculations handled for you.

Don't worry — we deal with it. Free HMRC enquiry representation is included, so your accountant manages the correspondence and defends your return without an extra bill landing on your desk.

Tax returns

Corporation tax & tax return service

Corporation tax (CT600), partnership and capital gains returns, calculated, optimised and filed before every HMRC deadline by a qualified accountant.

Corporation tax done right

Your company’s CT600 return reports its profits and the corporation tax due. We calculate it from your year-end accounts, claim every allowance and relief — from capital allowances to R&D where eligible — and file it with HMRC on time. Profits up to £50,000 are taxed at 19% and above £250,000 at 25%, with marginal relief in between.

Estimate your bill with our corporation tax calculator, then let us optimise and file it.

Partnership & capital gains returns

We also prepare partnership returns (SA800) and the partners’ individual returns, and handle capital gains tax on the sale of property, shares or business assets — making sure reliefs like Business Asset Disposal Relief are claimed where they apply.

Corporation tax is payable nine months and one day after your accounting year-end, and the CT600 return is due 12 months after. We file early so you can plan for it.

Yes — through capital allowances, pension contributions, R&D relief, the right salary/dividend mix and careful timing. Proactive planning is built into every plan.