ACER released two open letters on 22 April 2026 that ruled out any transition relief or simultaneity waiver for the recast REMIT Implementing Regulation and Delegated Regulation, which enter force on 29 April 1. The rule runs on transaction date: a contract traded on 28 April falls under the old one-month reporting window; the identical contract on 29 April falls under the new 14-day window, with no grace period between the two.
Compliance teams face a deterministic fork. The public consultation on the REMIT transaction reporting guideline opened 16 April and runs to 12 June , meaning market participants must comply from 29 April against guidance still open to formal revision. Any compliance error between 29 April and 12 June falls under the new rules regardless of whether the final guidance later changes the interpretation. ACER's practical transaction-date examples reduce ambiguity at the margin, but the LNG-specific Expert Group guidance remains entirely prospective. A new LNG Expert Group was established alongside tightened LNG transparency rules, with non-EU reporting intermediaries receiving no grandfather clause.
ACER's framework adds governance risk on top of supply risk. The new 14-day window compresses reconciliation cycles and removes buffer for late corrections. The venue-of-record for transactions moved through London or Geneva brokers has to be rewired inside a week. Coming into force alongside Friday's Russian LNG step , the compliance load sits at its peak just as the supply calendar tightens.
