Guide
Construction tax compliance - how CIS, VAT, CITB, and PAYE work together
An integrated view of construction industry tax obligations showing how CIS deductions, VAT reverse charge, CITB levy, and PAYE interact on the same payments. Includes worked examples demonstrating all obligations for typical subcontractor payments.
When paying subcontractors in construction, you must follow four tax rules: CIS deductions, VAT reverse charge, CITB levy, and PAYE. CIS applies to labour only, VAT reverse charge means no VAT on invoice, and CITB levy is based on your labour payments. Check subcontractor status and calculate deductions correctly.
- Apply CIS deductions to labour only, not materials
- Do not add VAT when reverse charge applies
- Mark invoices clearly with 'Reverse charge'
- Pay CIS deductions to HMRC by the 22nd
- Calculate CITB levy on PAYE and net CIS payments
- Exemption if PAYE + CIS under £150,000
- CITB rate 0.35% on PAYE, 1.25% on net CIS
- Check subcontractor CIS and VAT status
- Report reverse charge VAT on your VAT return
- Keep records of all payments and deductions
Construction businesses face multiple overlapping tax obligations when paying for labour and services. Understanding how CIS, VAT, CITB, and PAYE work together helps you comply correctly and avoid costly mistakes.
This guide shows how these four systems interact on the same payment, with worked examples you can apply to your own business.
The four construction tax obligations
When you pay subcontractors or employ workers in construction, you may need to deal with all four of these systems:
- CIS (Construction Industry Scheme) - tax deductions from payments to subcontractors, paid to HMRC
- VAT reverse charge - construction services between VAT-registered businesses where the customer accounts for VAT
- CITB levy - training levy based on your total labour payments (PAYE wages + net CIS payments)
- PAYE - income tax and National Insurance for employees (not subcontractors - but employment status matters)
The key challenge is that these systems overlap but are not identical. A payment to a subcontractor may involve CIS, VAT reverse charge, and CITB simultaneously. Getting any one of them wrong creates compliance risk.
How CIS and VAT reverse charge interact
When you pay a VAT-registered subcontractor for construction services, both CIS deductions AND the VAT reverse charge may apply to the same payment. Understanding how these interact is essential for correct accounting.
The key principles:
- CIS applies to labour - deductions are calculated on the labour element only, not materials
- VAT reverse charge means no VAT on invoice - the customer accounts for VAT on their VAT return instead
- CIS is calculated on the net (pre-VAT) amount - the reverse charge does not change CIS calculations
- Both systems use CIS registration as a trigger - the reverse charge applies to supplies between CIS-registered businesses
Key points from the worked example
The example above shows several important interactions:
- CIS only applies to labour - the 2,000 materials are paid in full, only the 10,000 labour element has the 20% CIS deduction
- No VAT appears on the invoice - the reverse charge means the contractor handles VAT accounting, not the subcontractor
- Contractor pays 12,000 total - 10,000 to subcontractor + 2,000 CIS to HMRC
- VAT is neutral for most contractors - Box 1 equals Box 4 if fully taxable
How CIS relates to CITB levy
The CITB levy is a statutory training levy collected from construction employers. Your CIS payment data directly feeds into your CITB levy calculation, but at a higher rate than PAYE wages.
Understanding this connection helps you budget correctly and explains why using more subcontractors increases your CITB costs.
Why subcontractor payments cost more in CITB levy
The worked example shows that net CIS payments attract a levy rate of 1.25% compared to 0.35% for PAYE wages. This is because:
- Subcontractors may not receive employer-funded training
- The higher rate compensates CITB for this training gap
- It incentivises contractors to invest in training or use trained subcontractors
Practical implication: When comparing the cost of using employees versus subcontractors, factor in the higher CITB levy rate on subcontractor payments.
CIS registration does NOT determine employment status
This is one of the most important - and most misunderstood - aspects of construction tax compliance. Being CIS-registered does not make someone self-employed.
CIS is purely a tax collection mechanism. A worker can be:
- CIS-registered AND genuinely self-employed - correct treatment
- CIS-registered AND actually an employee - compliance breach
- Not CIS-registered AND an employee - use PAYE
Getting this wrong exposes you to:
- Unpaid employer and employee National Insurance
- Employment tribunal claims for holiday pay, unfair dismissal
- Pension auto-enrolment failures
- Interest and penalties from HMRC
Worked example: All four obligations on one payment
Here is a complete example showing how CIS, VAT, CITB, and employment status checks all apply to a typical subcontractor payment.
Scenario
You are a main contractor paying a subcontractor for plastering work:
- Labour charge: 5,000
- Materials supplied by subcontractor: 500
- Both parties are VAT-registered and CIS-registered
- Subcontractor is registered (20% deduction rate)
- Your annual CIS payments will total 300,000
- You have verified the subcontractor's status
Step 1: Check employment status (before any payment)
Use HMRC's CEST tool to confirm the worker is genuinely self-employed, not an employee. Consider:
- Can they send a substitute?
- Do you control how they do the work?
- Do they work for other contractors?
If actually employed: Stop - use PAYE, not CIS.
Step 2: Calculate CIS deduction
- CIS applies to labour only: 5,000
- Deduction at 20%: 5,000 x 20% = 1,000
- Materials (no CIS): 500
Step 3: Apply VAT reverse charge
- Both parties VAT and CIS registered - reverse charge applies
- Invoice shows: 5,500 (no VAT)
- Annotation: "Reverse charge: Customer to account for VAT to HMRC"
Step 4: Calculate payment to subcontractor
- Gross invoice: 5,500
- Less CIS on labour: -1,000
- Pay subcontractor: 4,500
Step 5: Your accounting entries
- Pay subcontractor: 4,500
- Pay HMRC (CIS): 1,000 (by 22nd of following month)
- VAT return Box 1: 1,100 (reverse charge: 5,500 x 20%)
- VAT return Box 4: 1,100 (input VAT recovery)
- Net VAT effect: Zero (if fully taxable)
Step 6: CITB levy impact
The net payment (after CIS deduction) counts towards your CITB levy:
- Net CIS payment: 4,500
- Added to your annual CIS total for levy calculation
- At 1.25% rate: 4,500 x 1.25% = 56.25 annual levy impact
Summary: Your total cost for this 5,500 invoice
- Payment to subcontractor: 4,500
- CIS to HMRC: 1,000
- VAT: 0 net (reverse charge offsets)
- CITB levy contribution: 56.25
- Total cost: 5,556.25
Common mistakes when these systems interact
CIS + VAT mistakes
- Applying CIS to materials: Only labour is subject to CIS deductions - materials pass through at full value
- Charging VAT when reverse charge applies: If both parties are CIS and VAT registered, no VAT should appear on the invoice
- Applying CIS to VAT amount: CIS is always calculated on the net (pre-VAT) labour amount
CIS + PAYE mistakes
- Assuming CIS registration = self-employed: Employment status is determined by the nature of the relationship, not CIS registration
- Using CIS for regular workers: If someone works set hours, uses your tools, and cannot send a substitute, they may be an employee
- Ignoring IR35: Limited company contractors may still be "inside IR35" requiring PAYE treatment
CITB mistakes
- Forgetting CIS attracts higher levy: Budget for 1.25% on subcontractor payments, not 0.35%
- Excluding CIS payments from levy return: CITB uses your CIS return data - your figures must match
Timeline: When each obligation triggers
Understanding the timing helps you stay compliant:
Before first payment to a subcontractor
- Verify CIS status: Check with HMRC online service
- Assess employment status: Use CEST tool, keep records
- Confirm VAT status: Check if reverse charge applies
- Get end user confirmation: If reverse charge may not apply, get written confirmation
When you make a payment
- Deduct CIS: Calculate on labour element
- Issue payment statement: Within 14 days of tax month end
- Account for VAT: On your VAT return (reverse charge)
Monthly deadlines
- CIS return: By 19th of following month
- CIS payment: By 22nd if paying electronically
Annual deadlines
- CITB levy return: Confirm PAYE and CIS figures
- CITB levy payment: Per assessment (can be spread)
Checklist: Integrated construction tax compliance
Use this checklist for each new subcontractor relationship:
Before engaging the subcontractor
- Verify their CIS registration status with HMRC
- Assess employment status using CEST tool and document result
- Check their VAT registration status
- Determine if VAT reverse charge applies (both CIS registered, not end user)
- If they claim end user status, get written confirmation
For each payment
- Separate labour from materials on invoice
- Apply correct CIS deduction rate to labour only
- Check invoice shows reverse charge annotation (if applicable)
- Issue payment and deduction statement
Monthly
- Submit CIS return by 19th showing all payments and deductions
- Pay CIS deductions to HMRC by 22nd
- Include reverse charge VAT in your VAT return
Annually
- Review employment status of regular subcontractors
- Complete CITB levy return accurately
- Pay CITB levy as assessed
All four systems use different definitions
Be aware: CIS, VAT reverse charge, CITB, and PAYE each have slightly different scopes:
- CIS: Construction operations as defined in Finance Act 2004
- VAT reverse charge: Specified construction services reportable under CIS (with some exclusions)
- CITB: Construction activities under Industrial Training Act 1982 (slightly different list)
- PAYE/employment status: Based on nature of working relationship, not the type of work
A single worker relationship may require you to apply all four systems simultaneously. Check each obligation separately.
Related guides
- Register as a CIS contractor - how to register with HMRC before making your first subcontractor payment
- VAT reverse charge for construction - detailed guidance on when and how the reverse charge applies
- Calculate CIS deductions - step-by-step guide to calculating the correct deduction amount
- Submit your CIS monthly return - how to file your CIS300 return correctly
- CIS registration does not determine employment status - why CIS does not make someone self-employed