by mullet on Wed Dec 28, 2011 11:20 pm
The cost of the room conversion is not allowable, as it is capital expenditure. HMRC allows a flat rate deduction of £3 per week for heat and light etc. Guidance is at http://www.hmrc.gov.uk/incometax/relief-household.htm
If you are employed specifically to work at or from home, and have no alternative but to do so, you may be able to get tax relief on some of your household expenses. You can go back several years to get the relief - the time you've got depends on whether you've previously sent in a Self Assessment tax return.
If you have to work at or from home you can get tax relief for the extra household expenses that you have to pay. Typically these extra expenses include:
the extra cost of gas and electricity to heat and light your work area
business telephone calls
You won't be able to get relief on domestic expenses that you're paying anyway - like your mortgage or council tax. You also won't be able to get relief for expenses that relate to both business and private use - such as your telephone line rental, or Internet access.
You can get either:
A flat rate deduction of £3.00 per week (from 2008-09) for each week that you've got to work at home. This doesn't include the cost of business telephone calls.
A larger amount if your extra expenses are higher than £3.00 - but you'll have to show how you've calculated the figure.