The rights and obligations of an Access Responsible Party (or balance responsible party) are set out in an ARP contract.

What is an ARP?

For each access point there must be a designated balance responsible party. Either the supplier takes on the role itself or else it appoints an Access Responsible Party (ARP) which enters into a contract with Elia.

The ARP is responsible for maintaining quarter-hourly balance between total injections and total offtakes (including the HUB and Import/Export) of the grid users for which it has been designated as their ARP. The ARP may be a producer, a major customer, an energy supplier or a trader.

ARPs are authorised to perform their tasks under an ARP contract signed with Elia. Once authorisation has been granted, the ARP is entered onto the register of Access Responsible Parties.

The ARP contract sets out the balance-related rights and obligations of Elia and the ARP.


ARP contract

Before an ARP contract can be concluded, an application must be submitted to Elia (click on the following links to download the application form in English,  French or in Dutch).

The ARP must provide Elia with an access programm of all its injections and offtakes (known as nominations). It must do this at specific times, and no later than the day prior to transmission.

The following information must be supplied:

  • expected injections and offtakes (generation and consumption);
  • nominations for power exchanges between ARPs;
  • import and export nominations for the south and north borders.

The ARP's full portfolio of nominations must be balanced on a quarter-hourly basis. It must also be balanced in physical, real-time terms as far as possible.

Elia uses the measurement data to verify whether the ARPs are meeting their respective balance management obligations.



Elia will apply imbalance tariffs if it observes a quarter-hourly imbalance between injections, import and purchases on the one hand and offtakes, export and sales on the other.

ARPs can avoid imbalances resulting from an unscheduled event like a breakdown suffered by an industrial customer or a generation unit by:

  • exchanging energy on the 'intraday hub' on an intraday basis. In this case, they submit their nominations to Elia before noon the following day;
  • importing or exporting energy for the south border on an intraday basis (i.e. the same day).


More information