Jenbel, not sure of your employment status, i assume when you you say you work for them you are "employed" so it would not be a problem, but if you are "self-employed" and you do "work" for a client which involves travel and claiming back the costs there is a VAT cost implication.

You only need the e-receipt for claiming from a firm on internal expenses for the total you have paid out (claiming VAT is the accounts dept problem - not the coalface workers! ie there is none to worry about if you are an employee!).

It is a bit complex but ol' Hector describes it here:
http://www.hmrc.gov.uk/vat/charge-disbursements.htm

I am self employed and travel to places for clients to provide the service for which i charge, consequently i buy the tickets/hotels etc and have to charge VAT on the total sum as it is a service that VAT is applicable to! - i did say it was a bit complex.