Singapore’s third-quarter electricity revision produced four numbers that have been quoted interchangeably ever since — 17.0%, 17.5%, 31.91 cents, and 34.78 cents — and every one of them is correct. They measure different things, and a commercial building that budgets against the wrong one will misstate its own cost base by a wide margin.

What SP Group actually announced

On 30 June 2026, SP Group published the tariff revision for 1 July to 30 September 2026. Household tariffs rose 17.0%, or 4.64 cents per kilowatt-hour before GST, taking the household rate to 31.91 cents per kWh. The overall tariff, including non-households, rose by an average of 17.5%, or 4.66 cents per kWh. The gas tariff rose 7.1%, from 21.92 to 23.48 cents per kWh.

The Energy Market Authority confirmed to Channel NewsAsia that 31.91 cents is the highest household rate on record. The stated driver is elevated fuel costs following the Middle East conflict that began on 28 February 2026 — the previous quarter had absorbed only part of that, rising 2.1%, or 0.56 cents per kWh.

The four numbers, disambiguated

The 17.0% figure is the household increase. It is the number most widely reported, and it is the wrong one for a commercial portfolio.

The 17.5% figure is the average increase across all users including non-households. For a building owner, this is the closer proxy, though an average across a diverse user base is still not the same as any particular building’s outcome.

The 31.91 cents figure is the household rate before GST. The 34.78 cents figure is the same household rate with GST applied. They are one rate, quoted two ways — not a rate that moved between publications.

None of the four is a commercial rate. Non-household tariffs are set on their own basis, and a building’s effective cost depends on its contract, its load profile, and whether it buys from SP or a retailer.

Why the distinction is worth several hundred thousand dollars

Consider a building owner sizing a retrofit business case. Anchoring on 34.78 cents overstates the pre-GST energy cost that most commercial accounting treats as the comparable figure. Anchoring on 17.0% understates the increase relative to the 17.5% overall average. Combining them — taking a GST-inclusive rate and applying a household percentage — compounds both errors in the same direction, producing a savings estimate that will not survive contact with an actual invoice.

The error direction matters more than its size. Overstated savings make marginal retrofits look approved-worthy, and the correction arrives a year later when metered performance is compared against a business case built on the wrong base rate.

What to put in the model

Use the building’s own effective rate from its last full invoice, not a published tariff. The published tariff is a benchmark for direction and magnitude; it is not the price any particular commercial building pays.

Where a published figure is needed — for a board paper, a peer comparison, or a forward assumption — use the 17.5% overall average as the change, state that non-household rates are set separately, and quote rates on a consistent GST basis throughout the document. Mixing bases across a single table is the most common way this error enters a paper unnoticed.

What the revision says about direction

The underlying driver is fuel cost pass-through, which means the tariff will track global gas markets rather than a domestic policy cycle. A building owner planning capital works should treat the current level as a plausible floor rather than a peak, and should be sceptical of any business case whose payback depends on tariffs falling back to the pre-February range.

That is the useful conclusion from the revision, and it survives whichever of the four numbers is quoted — provided only one of them is quoted at a time.

Key takeaways

  • SP Group’s 30 June 2026 revision for 1 July to 30 September raised household tariffs 17.0% (4.64 cents per kWh) to 31.91 cents before GST, and the overall tariff including non-households by an average of 17.5% (4.66 cents per kWh).
  • 31.91 and 34.78 cents are the same household rate quoted before and after GST; they are not competing figures and should never appear in the same table on different bases.
  • None of the published headline figures is a commercial rate — non-household tariffs are set separately, and effective cost depends on contract, load profile, and supplier.
  • Retrofit business cases should be built on the building’s own effective rate from a full invoice, using the published 17.5% average only as a directional benchmark.
  • Because the increase is fuel-cost pass-through tied to global gas markets, the current level is better treated as a floor than a peak when sizing capital works.