There is one week to go until the first phase 1 REMIT data collection starts, which requires orders and trades arising out of activity on Organised Market Places(OMP) to be reported to ACER within a day that the activity took place. As of now there are 27 approved RRMs (which can be seen here). There is now a downloadable list of RRMs on the ACER website which can be accessed here. It contains a few more details than can be seen on the web site.
In general data will be reported by either the OMP itself or by a Registered Reporting Mechanism (RRM). In some cases, market participants have signed data reporting agreements directly with the OMP so that they report the data. In some cases, the OMP is sending data to a chosen RRM so that the market participant can route data via less places and in some other cases the market participant is uploading the data from the OMP and re downloading it to the RRM. The relative merits of each approach (and combinations of these) are examined in a market report produced by ETR Advisory and ComTech Advisory and can be accessed here.
Unfortunately though, not all OMPs will connect with all RRMs, which has made life harder for some market participants. Never the less market participants must make sure that arrangements are in place to be compliant within a week. A day or so after the deadline we will also know how well the systems put in place by OMPs, RRMs and ACER are functioning in production.