CIS REBATECLAIMSUK.
If you've had 20% CIS deducted from your labour payments and your actual tax liability for the year is less than the deductions you suffered, the difference is a rebate — and most subcontractors are owed one. The catch is which expenses you remember to claim and which year you file against. We match you with construction accountants who go four years back where it's legitimate, run the mileage and equipment numbers properly, and handle the EPS offsetting that limited company directors keep missing.
HOW A CIS REBATE ACTUALLY GETS RECOVERED
For sole trader subcontractors, CIS rebates flow through self-assessment. Total CIS suffered in the tax year (gathered from your monthly payment-and-deduction statements) goes onto the SA103S or SA103F as a payment on account; HMRC nets it against the income tax and Class 4 National Insurance owed on your construction profits. Profits = income minus allowable expenses, so the more legitimate expenses you claim, the lower the tax bill, the larger the rebate. Most subcontractors under-claim expenses because they don't track mileage or because they think tools "don't count" — both wrong.
For limited company subcontractor directors, CIS rebates flow through the EPS (Employer Payment Summary) under PAYE. CIS suffered each month is offset against PAYE/NIC owed; if the company's CIS suffered exceeds its PAYE bill, the excess can be carried back across the tax year to offset the earlier months' PAYE, and what remains can be claimed as a refund or offset against corporation tax via the CT600. Generalist accountants who don't do CIS regularly miss the EPS offsetting step entirely and end up reclaiming corporation-tax-side only — leaving CIS overpayment sitting in HMRC's name for months or years longer than it should.
Backclaiming is allowed for the current tax year plus the previous four. So in the 2025/26 tax year, you can still file or amend returns covering 2021/22 onwards. After four years HMRC won't process the claim; it's gone. We see this with subcontractors who came in mid-career, never filed self-assessment, and find out years later that they've been overpaying by 20% on every payment without ever reconciling.
Allowable expenses for construction subcontractors are broader than most realise. Vehicle running costs (fuel, insurance, MOT, servicing, depreciation or simplified mileage at 45p per mile up to 10,000 miles, 25p thereafter); tools and equipment (purchase or capital allowance depending on value); PPE and workwear (boots, hi-vis, gloves, safety helmets, branded clothing if it carries the firm's name); subscription and trade body fees (CITB, FMB, Federation of Master Builders); training courses that maintain or update existing skills; mobile phone and data plans for the business proportion; home office costs (a fixed £6 weekly allowance or a properly apportioned share of household bills); accountancy fees themselves. Mileage is the single biggest one most subcontractors under-claim — if you're working multiple sites, the trips between them are deductible.
Recovery timeline depends on the route. Sole-trader self-assessment: file the return, HMRC processes the SA refund usually within 4-12 weeks of submission. Limited company EPS offset: each month's CIS-vs-PAYE settles automatically in the next month's payroll cycle. Limited company refund: file the year-end EPS, HMRC repays the excess after the tax year closes (April 5th onwards, though the refund itself takes 4-12 weeks once requested). Backclaim amendments to old years: 8-12 weeks usually, longer if HMRC opens any kind of check on the amendment.
WHERE THE REBATE IS BIGGER THAN THE SUBCONTRACTOR REALISED
Site-to-site mileage is the biggest under-claimed category. If you're a subcontractor moving between two or three jobs in a week, the miles between site visits (and from your business base — which can legitimately be your home office for a sole trader) are deductible at 45p/25p. A subbie running 15,000 work-related miles a year is looking at £4,750 of mileage relief that translates into roughly £950-£1,900 of tax saved depending on their marginal rate. We routinely see new clients who've been claiming nothing.
Tools and equipment over £200 fall into the capital allowance regime — Annual Investment Allowance lets you deduct 100% in the year of purchase up to the AIA limit (currently £1m for the relevant tax years), which is more generous than most subcontractors realise. A new £4,000 plant kit, a £2,500 mitre saw setup, a £1,800 ladder system: all 100% deductible against profits in the year of purchase. Smaller tools (under £200, expensed as supplies) and consumables go on the regular expense line.
Training that maintains existing qualifications is fully deductible. CITB Site Safety Plus (SSSTS, SMSTS), CSCS card renewals, asbestos awareness updates, NICEIC re-assessments, gas safe registration renewals, working at height refreshers — all deductible. Training that takes you into a new trade isn't (HMRC's line is that it's capital, not revenue), but anything that maintains or updates an existing skill is fine.
Home office for sole-trader subcontractors is straightforward at the £6/week simplified allowance (£312 a year) and worth claiming even for site-only subbies who do paperwork at home. The full apportionment route (a percentage of household bills) gives more relief but generates Capital Gains Tax exposure when you sell the property if any room is exclusively used for business — most subcontractors find the simplified £6/week is worth claiming and the apportionment route isn't.
Mobile phone and data plans split into business proportion. If your phone is personal-and-business, claim the business-use proportion (typically 60-80% for a working subcontractor making site-coordination calls). If you have a separate dedicated business phone, claim 100%. Construction subcontractors without separate business phones routinely fail to claim anything; the proportion is allowable and HMRC accepts a reasonable estimate.
Reverse-charge VAT and CIS rebates interact for VAT-registered subcontractors. The reverse-charge mechanism means your construction-services invoices to other VAT-registered contractors don't include VAT, so the VAT side doesn't affect the CIS rebate calculation — but if you're also doing direct-to-consumer work (kitchen fitting for a homeowner, for example), that part of your turnover is normal-VAT and the reconciliation gets fiddly. Specialist construction accountants check the cross-line every quarter rather than letting it pile up.
REAL-WORLD CIS REBATE RECOVERIES
Subcontractor electrician, never filed self-assessment, six years working CIS at 20%. Of the six years, four were still in scope (2021/22 onwards). Annual income ~£42,000 with significant van, tool, and training expenses he'd never claimed. We filed all four returns, claiming mileage (12,000 work miles/year), tools (~£3,800/year average), training (CSCS + NICEIC renewals), home office, mobile, and PPE. Total rebate across four years: £14,200, against the £4,500 he'd initially expected. Recovery took 14 weeks for the first year, faster for subsequent years once HMRC had the pattern.
Limited company subcontractor with two working directors and £18,000/year of CIS suffered against £6,000/year of PAYE/NIC liability. Their previous accountant had been claiming the CIS on the CT600 only and had a £36,000 corporation-tax-side offset accumulated over three years that the company couldn't consume. We restructured to claim CIS through the EPS first (settling PAYE monthly with no out-of-pocket payment), backdated the EPS for the open year, and unwound the inflated corporation tax credit. Net cash freed up: £42,000.
Plasterer working across 4-6 sites a week between Hounslow, Harrow, Wembley and central London for two main contractors. Had been claiming the simplified flat-rate expenses without breaking out mileage. Reviewed his diary and Google Maps timeline data, reconstructed approximately 18,000 work miles a year. At 45p/25p that was £6,750 of mileage relief he'd been missing — about £1,350 of additional rebate for the open year. Plus three more years of similar exposure to amend.
CITIES WE COVER
Rebate recoveries vary by city because the trade mix and travel patterns vary. Where most work is mobile across multiple sites, mileage tends to dominate; where most work is single-site over a long contract, tools and equipment tend to dominate:
CIS Rebate Claims:Common Questions
Four tax years plus the current one. So in 2025/26 you can still file or amend returns covering 2021/22 onwards. After the four-year window closes the claim is gone — HMRC won't process it under any circumstance, including reasonable excuse. This is the single biggest reason to file even if you think you might not be owed much; the time-bar is hard.
Vehicle costs (mileage at 45p/25p, or actual costs with capital allowance for the van itself); tools and equipment (capital allowance for items over £200, expense for smaller); PPE and workwear; trade subscriptions (CITB, FMB, NICEIC); training that maintains or updates skills; mobile phone (business proportion); home office (£6/week simplified or apportioned); accountancy fees; and direct site costs not reimbursed by the contractor. The biggest under-claimed category by far is multi-site mileage.
Total CIS suffered in the year (from your payment-and-deduction statements) is netted against the income tax, National Insurance (Class 4 for sole traders), or PAYE/corporation tax (for limited companies) actually owed on your profits. If CIS suffered > tax owed, the difference is your rebate. Profits = income minus allowable expenses, so claiming all your legitimate expenses directly increases the rebate.
For sole trader self-assessment: typically 4-12 weeks from submission for the current year, longer for amendments to prior years (8-12 weeks). For limited companies via EPS, the offset against PAYE happens automatically each month; refunds of any excess after year-end typically arrive 4-12 weeks after the EPS is filed or the request lodged. HMRC system pressure during the January self-assessment peak slows the timeline; outside that window, claims process faster.
Yes — through the EPS (Employer Payment Summary) under PAYE first, then any remainder through the CT600 corporation tax return or as a direct refund. The EPS step is what generalist accountants miss; they reclaim the CIS suffered through CT600 only and end up with a corporation-tax credit balance the company can't consume. Claiming through EPS frees up cash month by month rather than at year-end.
For the four open tax years yes; for older years, no. We file the open years from scratch including all allowable expenses, claim the CIS suffered, and recover whatever is owed. There can be late-filing penalties on years that were due to be filed (generally £100 per year for missed self-assessment), but the rebate usually clears the penalties many times over and we appeal where reasonable excuse applies.
Yes. They're the evidence of CIS suffered and HMRC will ask for them on any review or check. Keep them for at least six years (HMRC's standard record-retention requirement). If your contractor isn't sending them — they're obliged to within 14 days of the tax month end — chase them; without statements you can still claim by reconciling your bank receipts against your invoices and HMRC's CIS records, but it's slower and the audit trail is weaker.
Yes. Accountancy fees relating to your construction business are an allowable expense — they reduce profits, which reduces tax, which increases the rebate. The fee for handling the rebate itself is deductible. Some accountants work on a percentage-of-recovery basis for CIS rebates, which is also fine to deduct as an expense in the year the work is done.