Will the MHHS transition stifle competition?

As you may now be aware, Market-wide Half-Hourly Settlement – or MHHS for short – is set to make a huge leap forward in how we match electricity supply to demand, with half-hourly consumption data being allocated to every UK consumer.

This is a major undertaking spanning four-plus years and impacting every consumer, all suppliers and meter operators – and lots more industry participants besides – that is being overseen by the energy industry regulator Ofgem.

If you are new to this concept, you can catch up with the fundamentals at our MHHS hub.

As MHHS is such an involved and lengthy process, different suppliers and meter operations will become ‘qualified’ to operate in the new MHHS model at different times over an 18-month-period, starting this October.

The question we often get asked – and one which we were keen to understand ourselves – is what will happen to customers who want to switch between suppliers where one has already migrated to the new MHHS model and the other is still using the current system?

Thanks to a new interim process confirmed by Elexon – the settlement body who’ll govern the new MHHS systems – ‘reverse migration’ will now be possible.

Reverse migration explained

Under this process, if you have been ‘migrated’ to the new MHHS system via a qualified supplier, then choose to switch to one that is not yet qualified, under the ‘Change of Supplier’ process, your MPAN can be reverted back to legacy practices and systems until such time it can be re-migrated to the new MHHS.

The aim is to ensure your meter and data collection remain supported, until your new supplier completes their own MHHS qualification.

In this way, the whole market can remain open for business and reduce the impact on consumers.

However, it’s worth noting that the reverse migration function will only be necessary between October 2025 – which is the official start of the 18-month migration window for suppliers – and the October 2026 deadline for qualification.

That said, the migration of your meter may still take time, as it will follow the timetable your supplier has agreed with Elexon.

Don’t forget to visit our MHHS hub if you’re looking for more information.