Elexon - Updated Approach to DTN File Numbering during Transition

In June 2024, Elexon published a Programme Participant Information Request (PPIR) in collaboration with the Programme to obtain information from Programme participants to understand the potential implications of the proposed approach to Data Transfer Network (DTN) File Numbering during Transition.

Following the feedback received from Programme participants, Elexon has revised their approach to DTN File Numbering during Transition.

Currently Elexon publishes Supplier Volume Allocation (SVA) Volume Allocation Runs (VAR) files via the DTN. This will continue as normal for settlement dates up to M10 Go-Live. After M10, processing of settlement dates will occur in the new Helix Volume Allocation Service (VAS) regardless of Metering Point Administration Number (MPAN) migration status. Across both SVA VAR and VAS systems, run numbers will be included in the header of each file produced for settlement. This means that during Transition, run numbers for settlement dates pre- and post-M10 will not increment relative to each other. For example, SVA VAR may be at approximately 70,000 with VAS only at 100 within a single calendar day. 

The main issue raised by several Programme participants via the PPIR was the duplication of run numbers. In the original proposal, VAS would start at Run Number 1, causing a duplicate run number error in participant systems that had already processed the ‘original’ Run Number 1 years ago.

Therefore, Elexon has suggested the following remedial actions to ensure no duplicate run numbers are sent:

• Calculating how many runs SVA VAR will be expected to execute to complete all settlement runs up to M10
• Adding this number to the current SVA VAR run number and then adding a buffer as a margin of error
• Setting the VAS run number to start from this calculated number

The following examples below have been updated to show VAS starting from 100,000 instead of 1.

If you have any questions about Elexon’s updated approach to DTN File Numbering during Transition or the examples below, please email Michael.Ceney@elexon.co.uk