Modifications to contracts

The Public Contracts Regulations 2015 provide clarity about the extent to which a contract can be amended after award without the need to re-advertise on Find a Tender Service. 

Permissible grounds for amended include;

  1. the existence of suitable “clear, precise and unequivocal” review clauses in the contract;
  2. or a need for additional supplies or services where a change of supplier cannot be made for economic or technical reasons and would cause significant inconvenience or substantial duplication of costs;
  3. or a need for additional deliveries due to unforeseen circumstances;
  4. or where a new supplier replaces the existing supplier because of insolvency or genuine restructuring.
  5. or if the value of the change is less than the procurement threshold and less than 10% of the initial contract value (for goods & services contracts) or 15% of the initial contract value (for works contracts) and the modification doesn't alter the overall nature of the contract.


Both (2) and (3) above are subject to a 50% maximum increase in contract value.

The Cabinet Office guidance on Amendments to Contracts During their Term provides a useful summary of the circumstances in which changes to contracts are and are not permissible.

General advice on the best way to ensure you can make changes to contracts during their term, without the need to retender, is to ensure your contract terms and conditions does have a ‘clear precise and unequivocal’ variation to contract clause.  It is generally accepted that for a variation clause to meet this test it would need to state the scope, nature and conditions under which a change to the contract could take place.  If possible it would be advisable for the variation clause to specify how the cost of the variation will be measured, preferably using rates in set out in the contract.  It may be worth seeking legal advice on the drafting of such a clause for contracts where you anticipate their might be modifications required.