recording and claiming expenses when making purchases for clients

I am a self-employed sole trader and work for different clients. They ask me to invoice for my time and then invoice for the equipment I purchase. For example they were invoiced £200 for hours worked and £100 purchasing equipment/ consumable resources for their site. When I enter the information on my tax return form do I enter it as ; £300 income because that is what is seen as going into my account and then do I deduct the £100 as expenses? Or do I enter it is £200 income only with no need to record my expenses?

Hi Jay Norton, 

You will iclude the £300 as income and then deduct the expenses. 

Thank you.