4.13 Procuring Authorities should be aware that any changes to services or project facilities should be captured by the payment mechanism. For example, an extension to project facilities should be covered by the payment mechanism where the PPP Contractor is to provide FM and lifecycle services even if the Authority paid directly for the extended facilities. Local agreements and non-documented changes should be avoided. For example, unofficially agreeing to different rectification periods. This approach can provide the foundation for future disputes.