Where gas is bought from a third-party supplier, the bill splits into supply (the commodity) and delivery (the local utility). Supply can be fixed-price or tied to an index plus a basis adder. Contracts that expire often roll to a month-to-month rate that is much higher.
The check
- Get the supply contract: term, expiry date, fixed or index, and the adder.
- From the bills, work out the supply price per MMBTU or therm for each month and plot it.
- A jump that lines up with a contract end, or a basis adder that changed, is the place to start.
Rebidding
- Start 60–120 days before expiry; ask at least three suppliers or a broker for fixed and index quotes.
- Ask for the adder in writing and how swing usage (cold months) is priced.
- If gas heats every apartment and isn't billed back, this cost is the owner's alone; it deserves a calendar reminder.