New rules to clamp down on market manipulation by forcing energy traders to report their transactions have now come into force.

Introduced in October, the first tranche of the EU’s REMIT (Regulation on Wholesale Energy Market Integrity and Transparency) data reporting rules required traders to report all exchange-based trades to the European Agency for the Cooperation of Energy Regulators (ACER).

The second tranche came into effect late last week, meaning traders now also have report over-the-counter – or bilateral – trades which take place outside of exchanges.

Whilst ACER is responsible for collecting the data, Ofgem is in charge of enforcing the rules in the UK. The first round was seen as being easier to comply with as much of the data was already collected by the exchanges, which were able to offer reporting services to traders. For over-the-counter transactions the data is held by the traders themselves.

Speaking to Utility Week last month, energy consultant Aviv Handler raised questions over how strictly Ofgem would enforce the rules if traders failed to comply by the deadline.