No one in their right mind will pay upfront. If you HAVE the money in hand offer to release it for a fee.

[We] are able to take on clients for 15% of the funds recovered, plus we need to pay for expenses (placing liens, Court fees, Bailiff fees), we can do this for 5% of the funds that each account holder has stuck. This has to be paid upfront.

Only a lawsuit filled on a contingency basis might be considered.

Only an idiot would pay 20% upfront ? court adjourned ...