The first stop for any British Gas complaint is the operator's own customer service. Call 0333 202 9802.

Most billing-related disputes resolve at this level. Have the bill in hand when you call, photograph your meter reading and date-stamp the photo on your phone, and have any prior ticket numbers ready.

Always get a complaint reference number. Without it, the complaint does not formally exist in the operator's system. Note it on the bill you are disputing.

If British Gas does not resolve within the statutory turnaround (typically 5-15 working days), escalate to Office of Gas and Electricity Markets.

The regulator's consumer-affairs office is at https://www.ofgem.gov.uk/. Most regulators offer an online complaint form; some also accept email and postal complaints.

Document the trail. Include the original bill, your complaint reference at the operator, the operator's response (or lack thereof), and any photographic evidence (meter readings, damaged seal, etc.).

The regulator's office is a quasi-judicial forum empowered to issue binding orders against the operator. Hearings are typically free of cost; you can represent yourself.

Disputed meter reading — Step 1 with photo evidence; typically resolved here. Wrong tariff classification — Step 1, escalate to Step 2 with property documents if denied. Overbilling on percentage levies — Step 1; document the arithmetic mismatch. Disconnection without notice — Step 1 with timestamped photo evidence; escalate to Step 2 if not resolved promptly. Outage compensation — Step 1 with outage log; escalate to Step 2 for binding compensation order.