Heat network data reporting: quarterly returns and the April 2026 backdate

Registration is only the start. Every registered network sends Ofgem data every quarter and every year, and the first return goes back to April 2026.

The deadlines

Quarterly data is due by the end of the month after each quarter closes: July, October, January and April. The annual return is due by 30 April. Extensions of one month can be requested.

What's reported

• Every quarter: residents in debt, disconnections, repayment plans, complaints by type and how quickly they were resolved, standing charges and unit rates
• Every year: customer and meter numbers, billing frequency, vulnerable residents, fuel type, the cost of heat, heat generated and delivered, revenue and running costs
• Organisation finances once a year, such as profit or loss and liquid assets. Local authorities and social housing providers are exempt from these; freeholders and RMCs aren't

The backdate

Because networks can register any time up to the deadline, Ofgem expects their first return to include data recorded from April 2026. If nobody has been keeping it, now is the time to start.

The service charge problem

Where heat is included in the service charge, Ofgem wants only the heat element reported. Separating heating costs out of a block's budget is the hardest part of reporting for most leasehold buildings.