Borrow on your gross income — before the 20% comes off.
Most lenders treat you as self-employed and judge you on net profit after expenses, shrinking what you can borrow. CIS-friendly lenders use your gross posted income from your payslips — and the figure is usually far higher.
Stuck between employed and self-employed
Under the Construction Industry Scheme, your contractor deducts tax at source — 20% if you’re registered, 30% if not — and pays it to HMRC. That leaves you in a grey zone most high-street algorithms can’t read: not quite employed, not a typical sole trader.
The result is that standard lenders default to treating you as self-employed and ask for two or three years of accounts. Those accounts show net profit after expenses, which understates your earning power — and if you’ve been subcontracting under a year, you may not have them at all. Either way, the door tends to close.
How do CIS-friendly lenders see it differently?
A group of specialist lenders assess CIS subcontractors closer to employed applicants. Rather than digging through self-assessment, they:
- Average your last three to six months of gross CIS payslips to estimate annual income.
- Use that gross figure — before the 20% deduction — as the basis for affordability.
- Apply an income multiple, commonly in the 4× to 5× range depending on the lender and profile.
- Accept payslips in place of full business accounts, which helps if you’re newly self-employed.
Gross vs net: what difference does it make?
Same earnings, two assessments
Net profit shown on self-assessment: £38,000
Self-employed basis at 4.5×: ≈ £171,000
CIS gross basis at 4.5×: ≈ £270,000
Same work, same money. Assessed on gross posted income, the borrowing rises substantially.
What documents do you need?
- Three to six months of CIS payslips or contractor statements.
- Three to six months of personal bank statements.
- Proof of CIS registration where applicable.
- Proof of deposit, identity and address.
- Latest SA302 and Tax Year Overview if you have them — useful, not always essential.
Estimate your borrowing
Enter your gross annual income below — the figure before the 20% CIS deduction — to see the borrowing it could support.
CIS mortgages, answered
What is a CIS mortgage?+
It is not a separate product — it is a mortgage assessed on the way Construction Industry Scheme subcontractors are paid. The right lenders treat you closer to employed, using your gross CIS income before the 20% tax deduction, rather than the lower net-profit figure from your tax return.
Can I borrow more on gross income than on my SA302?+
Usually, yes. Self-assessment accounts deduct business expenses and show net profit, which shrinks affordability. CIS-friendly lenders average your recent gross payslips instead, which is typically a higher figure — so the same income can support a larger mortgage.
How many payslips do I need?+
Most CIS lenders average your last three to six months of CIS payslips or statements to estimate an annual gross income. A clean, consistent run of recent payslips is often enough — even without two years of finalised accounts.
What if I’ve been subcontracting for less than a year?+
You still have options. Some lenders accept a shorter CIS history where your payslips and contract continuity support it, which is why subcontractors new to self-employment should speak to a specialist rather than assume a high-street decline is final.
Do I need to be a registered CIS subcontractor?+
Registered subcontractors have 20% deducted at source; unregistered ones face 30%. Being registered generally gives access to more lenders and a cleaner assessment, but advice is available either way.