Service level agreement
An SLA formalises the relationship between a bank's customer and its bank, by covering the minimum standards of service expected by the customer - including key performance indicators (KPIs) - and agreed to by the bank.
SLAs are also used between one bank and another. For example, where a bank provides services to its own customers indirectly, through a correspondent bank.
More generally, any similar agreement between a customer and a service provider.