Why not use the "business account" to purchase a new computer and then write it down as you would for Capital Expenditure! It would not be unreasonable to make a loss in the first year of trading. Certainly, I would agree that you can claim an allowance of £5.00 to £10.00 per week as "Premises Expenses", dependant on how often you are at home working, which is the appropriate box on the Self-Assessment form. This would be better indicated in your accounts as a contribution to "Gas and Electricity". If you try to designate part of your home as an office there are circumstances when you could fall foul of other taxes when you sell the house. Then you need to consider how you charge "internet fees", "telephone charges", etc to the Business. How often will you need to use your car, for simple things like going to the bank, always log the mileage and charge the standard rate of £0.40 per mile against the Business. The game is to ensure you get the most out of your Business without incurring tax!