As of today, bids submitted for aFRR and mFRR are by default indivisible if no attributes are utilized. This causes a number of indivisible bids, that are in reality not indivisible. To ensure, that the Nordic capacity markets for aFRR and mFRR are as efficient as possible, the Nordic TSOs are changing the implementation of indivisibility, such that the utilization of indivisibility is more explicit.
Indivisible bids are still allowed but using it going forward will demand an explicit action, where it from the BSP must be decided for each bid, what the minimum quantity to be accepted is.
The Nordic TSOs will implement the change in Autumn 2026. The final date will be published later.
From a technical point of view, what will happen is thus that The Indivisible Bids Allowed attribute will be removed. As a consequence, the bid attribute Minimum Quantity will be mandatory for every bid. You can find more specific information in the updated Implementation Guide for the Nordic FFR balancing capacity market.
All bids will therefore be considered divisible. A bid may be accepted or rejected either fully or partially. The accepted quantity may range from zero up to the offered quantity; however, any non-zero accepted quantity must not be lower than the bid’s Minimum Quantity.
If it is necessary to submit a bid as indivisible, this can be achieved by setting the Minimum Quantity equal to the offered quantity. Hence, if a bid of 10 MW is submitted and the minimum quantity is set to 1 MW, the bid will be seen as divisible between 1 and 10 MW. If the minimum quantity is set to 10 MW, the bid will be indivisible.
Please note that while a bid may specify different offered quantities for individual hours, the Minimum Quantity is defined once per bid and applies to all hours. Therefore, if the intention is to submit an indivisible bid with different quantities across hours, the bid must be split into multiple separate bids, each offering the same quantity in all hours. See the example below:
Other updates in the Implementation Guide
In addition to the change with indivisibility, two smaller changes are presented in the updated Implementation Guide.
Firstly, an adjustment to the bid format of exclusive linked bids is included, such that it is secured, that divisibility in cross-market exclusive linked bids is fully supported. This means that in the case where an exclusive linked bid across aFRR and mFRR are partly accepted in aFRR, the remaining volume of the bid is available in mFRR. This change is purely on the platform side, meaning that no adaption is necessary on the BSP side.
Secondly, the updated Implementation Guide introduces an implementation of a new time series, which contains information of the bid quantity rejected due to internal bottlenecks in the grid. Here BSPs should secure, that this information can either be received and processed or at least make secure that the new time series do not create any conflicts in internal processes.
The Nordic TSOs will implement these two updates expectedly in June 2026.
In case you have any questions to the content of the Implementation Guide, please reach out to .
In case you have any market related questions, please reach out to your national TSO-representative.