The MHHS baseline design moves the market segmentation to a combination of meter & connection type for settlement purposes so requires Traditional meter types with WC connections to be allocated to the Smart meter segment upon migration to the MHHS arrangements. This was a design choice to cater for most of the electricity market (where the customer choice of metering solution is not optional) because the largest number of Metering Systems is in the SVA market, the result of this means that

1. where non-domestic customer choice can be offered to non-domestic customers in line with Supplier Licence Condition (SLC) 39.13 & customers opt for Advanced metering solutions it creates a need for the Change of Market Segment (CoSeg) to be performed in line with a planned meter exchange date.

2. Where a customer (domestic or non-domestic) cannot be offered a choice of metering in line with Supplier Licence Condition (SLC) 39.13 but has an advanced meter installed in their premises, the Change of Market Segment (CoSeg) to be performed in line with a planned meter exchange date.

Consequently, when a WC connection goes through a MEX from Traditional to Advanced, or from Advanced to Smart in the MHHS arrangements a new complexity is placed on suppliers because the CoSeg process must be tightly co-ordinated to a specified planned MEX date and processed through the MPRS within 3 Working Days of that date, otherwise the CoSeg process lapses. This arises because suppliers initiate the CoSeg process only once a planned MEX date is agreed with the Metering Service provider which is to be appointed.

The complexity arises because the design removes the ability for the Metering Service to conduct direct customer contact to book MEXs in advance of a MEX as it is not appointed by virtue of the market segmentation being in conflict with the required type of meter that should be installed, e.g. an MSS agent appointment may only exist where Traditional or Smart meter is in place. Even if this was worked around (e.g. information shared via an information sharing web portal) the Metering Service could not proceed due to the lack of an existing appointment, so would have to come back to the supplier to initiate the CoSeg process, When compared to the legacy arrangements this has created additional burdens, increases the risk of failing to meet customer demand for their chosen meter solution, and ultimately acts to impede suppliers ability to meet its metering rollout targets.