The Complete CIS Mortgage Guide
Everything CIS Subcontractors & Tradespeople Need to Know About Getting a Mortgage
By Opus Mortgage & Protection Consultants
What Is a CIS Mortgage?
If you're paid under the Construction Industry Scheme (CIS), you're technically self-employed — but your income works differently to most self-employed workers. Many high-street lenders don't understand CIS income, which can lead to lower offers or outright rejections.
A CIS mortgage is simply a mortgage from a lender who understands how CIS payments work and will assess your gross contract income rather than relying solely on your tax returns or SA302s.
How CIS Income Is Assessed
Key Difference
Standard lenders use your net profit after expenses. CIS-specialist lenders use your gross contract income — meaning you can borrow significantly more.
What lenders typically need:
- ✓ 12 months of CIS payment statements (CIS vouchers)
- ✓ Bank statements showing CIS deposits (3-6 months)
- ✓ SA302 and tax year overview (some lenders only)
- ✓ Contract or confirmation of ongoing work
- ✓ ID and proof of address
Borrowing Power: CIS vs Standard
Standard Lender
Income: £50,000 gross CIS
Assessed as: £30,000 (net after expenses)
Max Mortgage: ~£135,000
CIS Specialist Lender
Income: £50,000 gross CIS
Assessed as: £50,000 (gross contract income)
Max Mortgage: ~£225,000
Common CIS Mortgage Myths
Myth: "I need 3 years of accounts"
Fact: Many lenders accept just 12 months of CIS vouchers.
Myth: "I can't get a mortgage with a small deposit"
Fact: CIS mortgages are available from 5% deposit with the right lender.
Myth: "My tax deductions reduce what I can borrow"
Fact: CIS specialist lenders use gross income before tax deductions.
Myth: "I need to go Limited Company first"
Fact: CIS sole traders and Ltd company directors can both apply.
Your CIS Mortgage Checklist
- 1Gather 12 months of CIS payment vouchers from your contractor(s)
- 2Get your latest SA302 and tax year overview from HMRC
- 3Collect 3-6 months of bank statements showing CIS deposits
- 4Check your credit report and fix any errors
- 5Calculate your deposit amount (minimum 5%)
- 6Speak to a CIS mortgage specialist broker (like us!)
- 7Get a Decision in Principle before house hunting
- 8Find your property and submit your full application
Ready to Get Your CIS Mortgage?
Speak with an adviser who understands CIS income and can compare lenders against your circumstances.