Contractor Guide

Contractor Day Rate Guide: Calculating Annual Income Correctly

How mortgage lenders annualize your day rate, the difference between 46 and 48 weeks, and worked examples at different rates.

Updated January 20268 min read

How Day Rate Annualization Works

When you're a contractor paid a daily rate, mortgage lenders need to convert this into an annual income figure for their affordability calculations. The basic formula is:

Annual Income = Day Rate × Days per Week × Weeks per Year

The variables in this equation — particularly weeks per year — vary by lender, which can significantly affect your borrowing capacity.

The key variable

The number of working weeks assumed is the biggest differentiator between lenders. 48 weeks vs 46 weeks on a £500/day rate is a difference of £5,000 annual income — or ~£22,500 in borrowing capacity.

Why Weeks Matter

Different lenders assume different numbers of working weeks per year:

48

weeks

4 weeks off
Contractor-specialist lenders

46

weeks

6 weeks off
Conservative mainstream lenders

44

weeks

8 weeks off
Very conservative (rare)

Days Per Week

Lenders typically use your actual contracted days. Most contractors work 5 days, but 4-day weeks are common. If you work 4 days at a higher day rate, this is usually accepted at face value.

Worked Examples

Example 1: £400/day, 5 days/week

48 weeks

£96,000

Borrowing: £432k

46 weeks

£92,000

Borrowing: £414k

44 weeks

£88,000

Borrowing: £396k

Difference between best and worst: £36,000 borrowing

Example 2: £500/day, 5 days/week

48 weeks

£120,000

Borrowing: £540k

46 weeks

£115,000

Borrowing: £517k

44 weeks

£110,000

Borrowing: £495k

Difference between best and worst: £45,000 borrowing

Example 3: £600/day, 4 days/week

48 weeks

£115,200

Borrowing: £518k

46 weeks

£110,400

Borrowing: £497k

44 weeks

£105,600

Borrowing: £475k

Difference between best and worst: £43,000 borrowing

Try our contractor calculator with your day rate

Lender Requirements

Common Requirements for Day Rate Treatment

  • Minimum contracting history: Usually 12-24 months
  • Current contract: Must be on contract or within 6-8 weeks of last one
  • Minimum remaining contract: Some require 3-6 months remaining
  • Contract documentation: Signed contract showing rate and terms
  • Outside IR35: Some lenders require this for day rate treatment

Contractor-Specialist Lenders

CLS Money / CMME

  • • 48 weeks annualization
  • • 12 months contracting history
  • • Broker-only

Kensington

  • • Flexible approach
  • • 1 year history
  • • Considers complex cases

Precise

  • • Multiple calculation methods
  • • Uses best for client
  • • Good for mixed income

Halifax/Nationwide

  • • High street options
  • • Competitive rates
  • • May use accounts instead

Broker recommendation

Many contractor-specialist lenders are broker-only. A broker experienced with contractors can access these lenders and knows which one suits your specific situation.

Calculate your contractor borrowing

Use our calculator to see your annual income under different lender approaches.

Try the calculator

Frequently asked questions