Income Guide

How Lenders Actually Calculate Self-Employed Income

A complete breakdown of the different methods UK mortgage lenders use to assess income for sole traders, Ltd company directors, and contractors.

Updated January 202612 min read

Why Income Calculation Matters

When you're employed, calculating your income is simple: your salary is your salary. But self-employed income is fundamentally different. Your "income" could be calculated in multiple ways, and different lenders use different methods.

The impact can be significant

The difference between the most favorable and least favorable calculation method can be tens of thousands of pounds in borrowing capacity. Two lenders looking at the same accounts might offer you very different mortgages.

Understanding how lenders calculate your income helps you:

  • Choose the right lender for your income structure
  • Optimize your accounts before applying
  • Set realistic expectations for borrowing
  • Have informed conversations with brokers

Sole Traders

As a sole trader, your income for mortgage purposes is typically your net profit — your business income minus allowable expenses. This is the figure that appears on your SA302 as "Profit from self-employment."

The Calculation

Total business income: £80,000

Less: Allowable expenses: £20,000

Net Profit (Assessable Income): £60,000

Key point for sole traders

Every pound you claim as an expense reduces your assessable income. If you claim an extra £5,000 in expenses, you save perhaps £1,000-2,000 in tax but reduce your potential borrowing by £22,500 (at 4.5x).

Multiple Years

Most lenders require 2-3 years of accounts and will either:

  • Average your profit across 2 or 3 years
  • Use the latest year only
  • Use the lower of the last 2 years

Ltd Company Directors

This is where income calculation becomes complex. As a director-shareholder, you have multiple income components, and lenders treat them differently.

Income Components

Salary

Your director's salary, typically low (around £12,570) for tax efficiency. Always counted by all lenders.

Dividends

Payments from company profits to shareholders. Most lenders count these.

Retained Profits

Profits left in the company. Only some lenders consider these.

Net Profit Share

Your percentage share of total company net profit. Some lenders use this method.

Common Calculation Methods

1

Salary Only

The most conservative approach. If you take £12,570 salary, that's your assessable income. Very few lenders use this anymore.

Example: Salary £12,570 = Assessable income £12,570 = Borrowing ~£56k
2

Salary + Dividends

The most common method. Lenders add your salary to dividends actually declared and paid to you. This is what most high street banks use.

Example: Salary £12,570 + Dividends £40,000 = £52,570 = Borrowing ~£237k
3

Salary + Share of Net Profit

The most favorable method for tax-efficient directors. Instead of looking at what you extracted, lenders look at your share of what the company made.

Example: Company net profit £100,000, you own 100% = Assessable income £100,000 = Borrowing ~£450k

Lenders using this: Nationwide, Halifax, Accord, Kensington, some building societies

The opportunity

If you're a tax-efficient director with retained profits, finding a lender who uses the "salary + share of net profit" method could dramatically increase your borrowing.

Contractors

Contractors with day rate contracts have a unique situation. Lenders can either treat you like a self-employed person (using your accounts) or use a day rate annualization method.

Day Rate Annualization

Some lenders simply multiply your day rate to get an annual figure:

The Calculation

Day rate: £500

Days per week: 5

Weeks per year: 48 (allowing 4 weeks off)

Annual income: £500 × 5 × 48 = £120,000

The number of weeks used varies by lender:

  • 48 weeks — Standard for contractor-specialist lenders
  • 46 weeks — More conservative mainstream lenders
  • 44 weeks — Very conservative approach

Requirements for Day Rate Treatment

  • Usually need minimum 12-24 months contracting history
  • Current contract or recent contract (within 6-8 weeks)
  • Contract documentation showing day rate
  • Some lenders require minimum contract length remaining
Try our contractor day rate calculator

Averaging Methods Explained

Most lenders require multiple years of income evidence. How they combine these years significantly affects your borrowing.

Simple Average

Add up the years and divide. Smooths out variation but might not reflect current position.

Year 1: £50,000

Year 2: £60,000

Year 3: £70,000

Average: £60,000

Latest Year Only

Uses your most recent year. Best if your income is growing.

Year 1: £50,000

Year 2: £60,000

Year 3: £70,000

Used: £70,000

Lower of Last 2 Years

Conservative approach — uses whichever is lower. Penalizes income dips.

Year 1: £50,000

Year 2: £60,000

Year 3: £55,000

Used: £55,000

Projected/Growing Income

Some lenders recognize growth patterns and may weight recent years more heavily.

Year 1: £50,000 (×0.5)

Year 2: £60,000 (×0.75)

Year 3: £70,000 (×1.0)

Weighted: £63,750

See your borrowing under different methods

Use our calculator to compare what different income calculation methods mean for your mortgage.

Try the calculator

Frequently asked questions