Auction based, day-ahead and long term capacity services

The IUK Access Agreement (IAA) is a contract where we offer capacity products via auctions on the PRISMA auction platform and, on occasions, subscription processes published by IUK. The IAA, its associated IUK Access Code (IAC), and the contract summary are available here1:

The IAA was originally designed for the sale of short-term capacity via day-ahead auctions of capacity originating from the mechanisms contained in the Congestion Management Procedures (CMP).

Issue 2 of the IAA became effective on 30 October 2015 and was developed to implement certain provisions of the CAM, BAL & INT network codes, including the sale of longer-term capacity auctions on the PRISMA auction platform, should there be any such long-term capacity available.

The quantity of capacity on offer will vary, depending on availability. We advertise the quantity of capacity available for the auction of standard capacity products on PRISMA in accordance with the auction calendar published by ENTSOG.

For details on accessing capacity, see our Buy Capacity page.

To purchase IUK Capacity, IUK requires shippers to sign the IAA contract along with the System User Agreement.  You will also need to be registered on PRISMA.

In October 2017, IUK consulted on Issue 5 of the IAA and the IAC, and Issue 2 of the SUA. We have now submitted the updated access terms to Ofgem and CREG and expect a decision by early March 2018. For information purposes only, the post-consultation versions of the IAA, IAC and SUA are available here;


1. The regulators' decision letters regarding our IAA can be found here: