If you have to work from home because your employer doesn't have an office or the job requires you to live away from the office you may be able to claim tax relief on the costs associated with your work.
However if you choose to work from home some or all of the time, even if there is an office you can go to, you cannot claim any tax relief on the costs of working from home.
If you are eligible to claim working from home costs these are most likely to be light and heating costs for the area you work in and business phone calls. You cannot claim for costs which are not exclusively business such as your rent, rates or broadband. You can either claim exact costs (and provide evidence of these costs) or claim the weekly set amount of £6 per week.
If your employer reimburses you for costs incurred then obviously you cannot claim for these as well but if they only pay a portion of the costs you can claim the balance.
You can only claim for these costs if you pay tax as you will be refunded by an adjustment to your tax code once the claim is approved, unless you are claiming for prior years when HMRC will provide a tax refund.
The claim for expenses which must be exclusively for business can be done online - this link will take you to the "Check if you can Claim" worksheet
If you have a specific uniform, work clothes or tools for your work you can claim tax relief for these. You can either claim a flat rate of £60 or the amount set for specific industries. Alternatively you can claim for actual costs by providing the receipts with your claim.
If you use a vehicle for work you can claim mileage at the approved mileage rate of 45p per mile for the first 10,000 miles, 25p per mile after this. If you use a motorcycles or bicycle the claim can be 24p per mile or 20p per mile respectively. This mileage claim covers all associated cost of running a vehicle so you cannot claim for any other costs. When claiming you must send a mileage log to HMRC stating the postcode for start and end of journey and the reason for the journey. You cannot, of course, claim for home to work mileage.
The other cost you may be able to claim is for professional membership fees if you have had to pay these to enable you to do your job or an annual subscription which is relevant for your job. HMRC will only pay these fees if they are to professional organisations which they have approved and with copies of the receipts. Needless to say if your employer has paid these fees or reimbursed you there is no claim to be made.
If you have to travel for work and you are not reimbursed for those expenses you can claim for these too, again providing the receipts as evidence. The purchase of equipment needed to do your job, such as a laptop, which has not been reimbursed to you can also be claimed.
For further information visit HMRC website - Claim tax relief for your job expenses.