CIS Accountants London — Construction & Subcontractor Tax Specialists.
Specialist Self Assessment for CIS subcontractors and construction tradespeople across London. Fixed £350 per year, every allowable expense claimed, refund chased into your bank, certified SA302 + Tax Year Overview free for mortgage applications. By chartered accountants who file hundreds of CIS returns annually — Mon-Sat 10am-7pm with same-day callback.
Sound like your CIS situation?
Most CIS subcontractors we onboard arrive with the same handful of problems. We sort them in one engagement.
"My CIS deduction statements are everywhere"
Some contractors send monthly slips, some quarterly, some only at year-end, some never. You've got bits in WhatsApp, bits in the van, bits in old emails. We chase whoever's missing and pull deductions direct from HMRC where needed.
"I think I'm owed a refund but I don't know how much"
20% (or 30%) deducted at source from your gross — without expenses applied. The actual tax you owe is calculated on profit, not turnover. Most CIS subbies are due £1,200-£3,500 back. We file early so the refund hits your account within 2-4 weeks.
"My broker keeps asking for SA302"
Mortgage lenders want certified SA302 + Tax Year Overview to verify self-employed income. We produce both inside 24 hours of filing, certified by chartered accountant, in the format every UK lender accepts. Free for our CIS clients.
"I left it too late last year and got fined"
£100 automatic penalty for late filing. We work with subcontractors throughout the spring and summer to file early — refund earlier, no penalty risk, and breathing room before the January cliff edge.
"I'm not sure I'm claiming everything I should"
Tools, vehicle costs, mileage, PPE, training, public liability, work clothing, phone, materials, sometimes home office — we prompt for everything claimable. Most subbies miss £500-£1,500 of allowable expenses doing it themselves.
"Should I be a Limited Company by now?"
If your net profit is consistently above £40-50K, a limited company structure usually saves tax. We model your specific numbers in our £395 Tax Planning Workshop and handle the conversion if it's the right call — no pressure either way.
Your CIS Self Assessment, handled end-to-end.
No back-and-forth, no chasing, no surprise charges. One fixed fee, one accountant, one number to call.
The LOYALS CIS Self Assessment service
You're a subcontractor working under the Construction Industry Scheme. Each contractor you've worked for has deducted 20% (or 30% if you're not CIS-verified) from your gross earnings before paying you. That deduction is calculated on your turnover — but the tax you actually owe is based on your profit, after allowable business expenses. The gap between the two is usually a refund. Every year. For most CIS subcontractors in London, that gap sits between £1,200 and £3,500.
Our job is to capture every deduction, claim every allowable expense, file your Self Assessment correctly with HMRC, and chase the refund into your account. We also handle anything connected to your tax position — mortgage paperwork, MTD readiness for April 2026, limited company conversion when the numbers stack up. You don't pay extra for any of it. Fixed £350 per year, no add-ons.
Fixed £350 per tax yearTwo ways to file with us. Same standard.
From April 2026, MTD for Income Tax becomes mandatory for self-employed CIS subcontractors with income above £50,000. Below the threshold, annual filing continues as normal.
Annual CIS Self Assessment
- Self Assessment filed with HMRC
- All CIS deductions reconciled
- Every allowable expense claimed
- Refund chased to your bank
- SA302 + Tax Year Overview free
- Year-round phone & WhatsApp support
- £250 for additional past years to catch up
MTD Quarterly + Final Declaration
- 4 quarterly digital submissions to HMRC
- Final declaration at year-end
- MTD-compatible software setup
- All CIS deductions captured digitally
- Every allowable expense claimed
- SA302 / Tax Year Overview equivalent
- Total annual cost: £600
Everything you need, nothing you don't.
Most accountants quote £350 then add £40 here for SA302, £25 there for an accountant reference. Ours is genuinely fixed.
Self Assessment filed with HMRC
Self-employment pages with full CIS reconciliation, employment pages if you have any PAYE, plus interest, dividends, property — whatever applies.
CIS deductions retrieval
If your contractors haven't sent statements or you've lost them, we pull deductions directly from HMRC's records — no chasing for you.
All allowable expenses claimed
Tools, van costs, mileage at 45p/mile, PPE, public liability insurance, training, work clothing, phone, materials, home office where applicable.
Refund chased into your bank
Filed with bank details, electronic refund 2-4 weeks. We chase HMRC directly if the refund is delayed beyond the normal window.
SA302 + Tax Year Overview free
Both produced and certified by chartered accountant, accepted directly by every UK lender. Usually £40-£80 elsewhere — included free with us.
Mortgage broker liaison
If you're applying for a mortgage we coordinate directly with our partner FCA-authorised brokers, sending the SA302 pack and accountant references they need.
Year-round support included
Question about an HMRC letter mid-year? Worried about a contractor going under owing you money? WhatsApp us — included in your £350, no per-call charges.
Limited Co conversion modelling
If your profit is climbing past £40-50K, we'll flag it and offer you our £395 Tax Planning Workshop to model the limited company alternative for your numbers.
Four steps from "I haven't filed" to refund in your bank.
From WhatsApp to HMRC submission usually takes 4 working days once we have your records. Refund follows 2-4 weeks after.
Sign engagement
Online engagement letter, fixed £350 confirmed upfront. Takes 5 minutes on your phone, no paper to print.
Send your records
WhatsApp, email, secure portal, or come into our King's Cross office. CIS statements, bank statements, expense list, mileage.
We file with HMRC
Within 4 working days. Every CIS deduction reconciled, every allowable expense claimed, refund triggered with your bank details.
Refund hits your bank
2-4 weeks after filing. We send you the SA302 + Tax Year Overview pack ready for any mortgage broker who asks.
Three reasons we're not just another accountant.
CIS is its own world. Most generalist accountants charge £400-£600 to file a return they don't really understand. We file hundreds every year.
CIS is our specialism
Construction industry tradespeople — bricklayers, plasterers, carpenters, electricians, plumbers, groundworkers, decorators, scaffolders, roofers — make up the largest single segment of our client base. We know your trade-specific expenses, your contractor types, your invoicing rhythms.
Mon-Sat extended hours
You work site hours. We're open Monday to Saturday 10am to 7pm so you don't have to take time off to deal with your tax. WhatsApp us on the way home from a job, get a same-day callback if needed.
Fixed £350, no surprises
Most accountants quote a base fee then add for SA302, accountant references, mortgage broker liaison, and "complexity surcharges". Our £350 is genuinely all-inclusive — and the inclusion list is on this page. You don't get a bigger bill at year-end.
How big is your refund likely to be?
Tell us what landed in your bank from contractors and we'll work out your indicative refund — including back-calculating your gross income before CIS deduction. For a precise calculation including student loans and Plan 5 thresholds, use our full CIS Tax Calculator.
Estimate your CIS refund
For an exact figure including Class 4 NIC, student loan, and Personal Allowance taper above £100K, run our full CIS Tax Calculator or send us a WhatsApp with your numbers.
Three things that have shifted how CIS gets taxed.
If your information about CIS comes from before April 2024, the rules have moved on. Some changes save you money, some create new compliance work — all of them affect your refund and your forward planning.
Class 4 NIC reduced
Class 4 National Insurance for self-employed (including CIS) cut from 9% to 6% from April 2024. Saves a typical CIS subcontractor on £35K profit roughly £675 per year. Many subbies are still using accountants applying the old rate — check your last return.
Class 2 NIC abolished
Class 2 NIC abolished as a paid contribution from April 2024. Self-employed earnings now build NI credits automatically without the £179.40/year charge — saves another small chunk and removes an admin step.
MTD for Income Tax
From April 2026, sole traders (including CIS subcontractors) with income above £50,000 must keep digital records and submit quarterly to HMRC. Threshold drops to £30,000 from April 2027. Need MTD-compatible software and quarterly filing rhythm. We handle it for £150/quarter.
Six things every CIS subcontractor should understand in 2025/26.
Tap any card to flip and see the detail.
How CIS deduction works
20% standard, 30% if you're not CIS-verified.
Tap or hoverWhat gets deducted
- 20% of your labour invoice (verified)
- 30% if not CIS-registered
- Materials separated, not deducted
- VAT excluded from CIS calc
- Goes against your final tax bill
Allowable expenses
Everything wholly and exclusively for your trade.
Tap or hoverCommon claims
- Tools and equipment
- Vehicle costs or 45p/mile
- Public liability insurance
- Work clothing & PPE
- Phone, training, accountant fees
Why subbies get refunds
CIS deducted on turnover, real tax owed on profit.
Tap or hoverThe refund maths
- 20% deducted on gross labour
- Real tax: 20% on profit (after PA)
- + Class 4 NIC at 6% above £12,570
- Gap = your refund
- Average £1,200-£3,500
SA302 for mortgages
The HMRC document lenders ask for.
Tap or hoverWhat we provide
- SA302 + Tax Year Overview pack
- Certified by chartered accountant
- Accepted by all UK lenders
- Free for our CIS clients
- Issued 24h after filing
Filing deadline
31 January for the previous tax year.
Tap or hoverPenalty schedule
- £100 automatic late filing
- Daily £10 after 3 months
- +£300 or 5% after 6 months
- +£300 or 5% after 12 months
- 5% surcharges + interest on tax
CIS to Limited Company
Worth modelling above £40-50K profit.
Tap or hoverThe trade-offs
- Salary + dividend tax efficiency
- Profit retention at 19-25% CT
- More admin (Companies House)
- Mortgage harder until 2yr accounts
- Workshop modelled at £395
Meet Kris Nick.
Kris is your dedicated account manager for CIS — and the LOYALS team specialises in construction tax because too many subcontractors were losing money to accountants who didn't really understand CIS. From the first onboarding call to the moment your refund clears, you'll have direct WhatsApp access to Kris and the team. We work alongside London tradespeople — bricklayers, plasterers, carpenters, electricians, scaffolders, groundworkers, decorators — every single day. Your CIS return isn't a side gig for us; it's the core of what we do.
Book a call with Kris →Stop overpaying on a return your accountant doesn't specialise in.
If you're a CIS subcontractor in London, our £350 fixed fee includes everything you need — return filed, refund chased, SA302 produced for your mortgage, and a chartered accountant on WhatsApp through the year. Sign up online in 5 minutes, send your records when you're ready, refund in your account within a month.
Frequently asked questions.
Updated for 2025/26 tax year. If your question isn't here, message us on WhatsApp or book a free 15-minute call.
Related LOYALS pages
Other services and tools that pair well with CIS Self Assessment.
Ready to file your CIS return properly?
£350 fixed, refund chased, SA302 free, mortgage broker liaison included. Sign up in 5 minutes and we'll have your return filed within 4 working days of receiving your records — refund in your bank within a month. Mon-Sat 10am-7pm extended hours, same-day callback.
Book my free 15-min call →