Nichola Ross Martin's Tax Consultancy

Use of home as office calculator

This use of home calculating tool is part of our Working from home toolkit.

It is designed for use by a self-employed person in order to calculate how much to claim as a tax deductible expense for working for home.

Alternatively a claim may be made without receipts for £3 per week for home working

Warning: 

1. Each expense claim will be different and each must be decided according to its own facts.
2. This calculation requires a degree of common sense combined with use of judgement and an understanding of both the type of business conducted and tax law. It is recommended that you read Working from home (self-employed) in conjunction with this kit.
3. Tax penalties will apply in the event of carelessness.
4. You must always try to retain evidence of proof of expenditure incurred (bills paid etc)

Expenses can be apportioned on different basis. This toolkit calculates expenses on the basis of number of rooms and hours. A more accurate calculation may create a more favourable result when taking into account actual usage and other factors as considered in the guide Working from home (self-employed).

Calculation

Step 1 working hours

• What type of work do you do?
• Is the business based at your home?
• Do you do work elsewhere?
• Does the business occupy other premises?
• Do you employ any employees?
• Do they also work at your home?
• Considering the responses to the above questions: for how many hours is your home actively used for work per day?
• If you also work away from home, how many hours do you work away from home per day?

Step 2 working rooms

• How many rooms are there in your house?
• How many rooms do you use wholly or exclusively for work?
• Do you use these rooms for private purposes during the evening or weekends?
• How many rooms do you use partly for work and partly for private use?
• Do you use any rooms for wholly or exclusively for work storage?

Step 3 working costs

Add up you costs:

Calculation

Full-time workers

If your total at Step 1 is more than 7 hours (assuming that you work from home full-time)

Take the combined totals from Step 3 and divide by Step 2 A, then multiply by (B + 1/2 x C)

Where you are also using rooms privately - say at weekends or in the evening you should consider restricting the claim proportionately.

Part-timers

If you are not working full time from home you may need to restrict your claim if you are not using rooms wholly or exclusively for the business. This calculation time apportions the claim over 24 hours. It may be more beneficial to work out usage on an expense by expense basis, see Working from home (self-employed)

If your total at Step 1 is less than 7 hours:

Take the combined totals from Step 3 and divide by Step 2 A, then multiply by (B + 1/2 x C). Multiply the result by your total hours at Step 1 and divide by 24.

Note on expenses

Telephone costs are not included in this calculation as it is assumed that the business would either support a dedicated phone line or that any claim for the use of a private be claimed separately based on actual use.