That being said there is no internationally established or consistently applied definition of P4P to date. In most definitions of P4P, performance and/or quality improvement are common themes (see Table 2.1). Unlike ex-ante add-on payments, which are applied prior to provision of services and/or are automatically applied to certain processes (i.e. providers understand that certain listed services will receive additional payment), add-on payments for quality are focussed on the degree of achievement of certain defined objectives by providers or practitioners, hence the “performance” dimension.