In certain circumstances, where two parties have monetary debts against each other, the right to set-off may arise. A right of set-off allows a (“Party 1”) to take into account the amount owed to it by the second party (“Party 2”) against any amount owed by Party 1 to Party 2, each party must be a debtor and a creditor.

Common law provides the key features that must be present for set-off to arise are;

1. mutuality of debts (each party must be the sole beneficial owner of the debt it is owed and the sole person liable for the debt it owes)

2. the claims each party has must be for non-payment of money

The common law provisions of set-off can be greatly enhanced by the inclusion of a contractual right to set-off (this is discussed further below) so that set-off is applicable in a greater range of situations. If you envisage set-off being a useful right it is not advisable to rely on the implied ability to use it (via common law or equitable set-off). Common law and equitable set-off are subject to various conditions and limitation however, a contractual right of set-off can be drafted to ensure parties are able to agree exactly how and when set-off should be applied.

In the above scenario, the supplier owes the manufacturer the payment for damages, while the manufacturer owes the supplier the payment for goods. This is mutuality of debts, which leads to right of set off.