Can my employer make me work away from base location, but not pay my additional travel expenses?

My company is based in London, but my company want me to travel out of London to work with clients. This costs me more in travel expenses, but they will not pay me expense of additional travel.

Is this legitamate?

Yes, absolutely. Most companies would reimburse travel expenses away from your usual base, but there is no legal requirement for them to do so. Check your contract and employee handbook to see if says that they will reimburse, as if it does then they will have to honour that, but if it isn't mentioned then unfortunately they can expect you to travel without repayment.

It depends on how the contracts are set up. Most companies will reimburse certain travel expenses during work hours to and from clients. It also depends on the field that you are in. If you are not traveling far from London, they may say that your additional travel expenses are too small to reimburse.

It depends on your contract, have a read through and check. Chances are its in there somewhere (in small print obviously). But, if its not then you can claim expenses.