People searching for the highest or lowest STC price ever usually want one of two things: a sense of how risky the market is, or a way to judge today’s price. Both are answered by the same shape. The upper end is fixed by regulation, and the lower end has been well below it only once.
The highest: $40
The Clearing House sells at $40 excluding GST, a fixed price set in regulation. A buyer can always purchase there, so the open market has little reason to trade above it. The spot price has hovered just under the ceiling for long stretches. In 2013, for example, the spot price reached $39.40 in early September before easing to $38 in late October.
So the highest STC price is, for practical purposes, $40. Anyone quoting a price above that for a certificate is either including GST ($44) or talking about a different certificate. See GST on STC prices.
The lowest: the early years
Open-market STC prices have fallen well below $40 only in the scheme’s early period, when creation exploded after the 2011 split and the system was oversupplied. Reported historic lows are around $16 to $17 a certificate. Treat that as an approximate figure, since broker charts and secondary sources differ, and check the Clean Energy Regulator’s publications for a verified series.
The scheme’s design was adjusted afterwards, and the market has held much closer to the ceiling in recent years. The background is in the history of the STC scheme.
What the range tells you
A ceiling at $40 and a historic floor in the high teens means the realistic range for an STC today is narrow. At the time of writing the spot market has been roughly $38 to $40, near the top of that range. The risk is not a collapse to the high teens, but a slow widening of the gap below $40 if supply outruns demand, as we describe in what drives STC prices.
Prices for other certificates behave differently
Compare this to LGCs, which have no ceiling and have swung from far higher levels to roughly $6 to $9 in September 2026. VEECs have hit a record near $110. Our comparison of STC, LGC, VEEC and ESC prices shows how different the ranges are.
What this means for installers
For job pricing, assume you will receive something close to the top of the range, but quote with the published rate in hand, not the historic high. Our daily rate is on the pricing page, and what an STC is worth in 2026 tracks the current position. For the basics of how trades work, see STC trading.