A new law could stop big firms using contracts in clauses to prevent smaller suppliers using invoice finance.
Some big firms do not like invoice finance as the lenders chase them in respect of unpaid invoices. But the Small Business, Enterprise and Employment Bill introduced in June 2014 will outlaw the use of such "bans on assignment".
The Asset Based Finance Association says the clauses are often used in the retail sector. Chief Executive, Jeff Longhurst, said: "This will free up small businesses to use what is often their biggest asset - their unpaid invoices - to get the finance to grow, invest and create jobs."