I cannot stress this enough! Do your due diligence on any company you take on as a client.
Check they are solvent - get more than one reference esp when a lot of money is involved. Do not feel scared to ask. Anyone honest will completely understand why you need to do checks. It is only the dodgy people who would kick up a fuss.
You will save a lot of heartache. I am single with a 3 year old daughter and face losing my home because a client will not pay me the money they owe me for commission and have no intention of ever paying me. They have breached their contract with me on so many levels.
If you have no money to get a lawyer, you can't enforce your agreement.
I continue to fight on but believe me, its a nightmare.
p.s. there are lots of solicitors out there who will help you with legal agreements and pay later. Make sure you get a lawyer's view on whatever agreement you make and sign with someone else.