14 To ensure continuation of service and achievement of the partnership's objectives, NS&I, with SBS, has developed a programme to support SBS's actions to improve its financial position. As part of this programme, NS&I has realigned contract terms to ensure the contract is clearer, less ambiguous, fairer and is a driver for a low cost operation through discouraging non-partnership behaviour by NS&I and SBS. In particular, NS&I has refined the Key Performance Indicators regime and it will share in the costs of developing new products and channels whilst both parties are incentivised to minimise development costs. A new set of milestones have been agreed which SBS is now delivering against on schedule. The contract realignment does not materially change the allocation of risk as the key risks of costs of operation, modernising the business and delivering the service remain with SBS.
15 Despite SBS's financial position, NS&I has not increased the unitary charge agreed in the contract and SBS has continued to deliver. Siemens AG is acting as a guarantor for SBS's obligations under the contract and has liability to pay NS&I up to £250 million in the event of default.