Guarantors and other insurers agree to pay money to identified parties if a specified event (a claim) occurs, in exchange for payment of an up-front premium. Guarantees usually take the form of one party agreeing to step into another's shoes if it fails to fulfil its responsibilities. For example, if a municipal government agrees to buy all the water produced under a BoTT structure but fails to do so, its obligation may be guaranteed by the provincial or national governments, or even by a multilateral development bank. They would then have to pay for the water. Insurance is similar, but is usually based on the occurrence of specified risks such as war or expropriation of assets. Major areas for negotiation here include whether and/or on what basis guarantors or insurers will accept responsibility to cover specified risks. Increasingly, national governments are disinclined to provide guarantees for municipal financing, leaving it to lenders and municipalities to work out for themselves whether a borrower is creditworthy and a project viable.