Demand guarantees developed to replace money deposits, which sellers had to provide to buyers in order to secure the latter against the former's default under the contract. The substitution of money deposits by demand guarantees helped account parties to maintain their liquidity: they were no more forced to tie up their money for a considerable period of time pending completion of the underlying contracts, and where the account party had no sufficient money to pay an upfront deposit it was relieved from the expense of borrowing cash from a banker and paying interest on the loan during its life. The account party also benefits from the low cost of demand guarantees compared to other instruments such as accessory guarantees.