Category A hits $133,009. The number that matters more is 19,085.

Category A closed at a record $133,009 in the 9 September bidding exercise, up $4,508 from $128,501. Category B rose to $135,001 from $131,001, and Category C for goods vehicles and buses moved to $93,101 from $90,002. Motorcycles closed at $12,556 and the Open category reached $137,890.

There were 4,776 bids against a quota of 3,253 certificates, which is 1.47 bidders for every certificate available. That ratio is the mechanism. Nothing more complicated than it is happening.

The number worth reading

The quota for the August to October period is 19,085, an increase of 0.2 per cent on the previous quarter's 19,052.

That figure needs reading carefully, because it hides two forces pulling in opposite directions.

Deregistrations are rising quickly. Cars registered in 2016 are reaching the end of their COE, and in Category A the number deregistered over the latest twelve months reached 33,941, up 37% on a year earlier. Each quarter's quota is based on a rolling average of deregistrations, so this adds supply.

At the same time, the additional certificates LTA has been injecting since February 2025 are tapering off. In Category A they fell from 2,246 in the November to January quarter to 200 in this one.

The two roughly cancel out, which is why the quota barely moved. Demand rose into a supply that did not, and the premium followed.

For anyone waiting for supply to ease premiums, the useful point is that the deregistration wave is real and already under way. Whether it shows up in the quota depends on how far the injections continue to fall. The November to January allocation, due in late October, will show which force is stronger.

The gap between the categories has almost gone

Category B sits at $135,001. Category A sits at $133,009. The difference is $1,992.

Through 2025, a Category B certificate cost on average about $17,800 more than a Category A one. Since February this year the difference has averaged about $2,400, and in three exercises Category B closed below Category A.

Part of the reason is supply. Over the last four quarters, LTA's Category A quota has fallen by about 7% while Category B's has risen by about 16%.

In practical terms: Category A is for cars up to 1,600cc with power output up to 97kW, and Category B is everything above that. For years, choosing a Category A car meant accepting a smaller, less powerful car in exchange for a clearly cheaper certificate. This year that saving has been small and unreliable.

It does not mean everyone should buy a bigger car. Road tax scales with engine capacity and does not follow the COE, and a 2.0 litre car costs meaningfully more to tax and fuel over a decade than a 1.6. But the certificate is no longer doing much of the work in that decision.

What this does to renewals

Anyone approaching the ten year mark pays the Prevailing Quota Premium, which is a rolling three month average rather than the latest close. The August exercise carried a September Category A PQP of $126,208 and a Category B PQP of $128,697.

A record close in September feeds into the October figure and pushes it up. How far depends on which rounds drop out of the average, and the honest answer is that you should read the October number on OneMotoring rather than take an estimate from anyone, including us.

What is worth saying plainly is the direction. If you are deciding between renewing and deregistering in the next few months, the renewal side of that comparison is getting more expensive, and the PARF rebate you forfeit by renewing does not move to compensate. We set out the full comparison in What happens at the ten year mark, renew, scrap or sell.

What this does to used prices

Nothing directly, and this gets stated wrongly constantly.

A rising COE does not raise the paper value of a car already on the road. The COE rebate is calculated against the premium paid when that car was registered, not against today's $133,009. A car registered on a $92,000 certificate has its rebate worked out on $92,000 regardless of what happened this afternoon.

The effect runs through demand instead. Higher premiums land on the on-the-road price of every new car registered against them, buyers priced out of new arrive in the used market, and dealers pay more to acquire replacement stock. Used prices follow, with a lag of a round or two, and they follow in both directions. We covered the full mechanism, and what it does to the quality of available stock rather than just the price, in COE is back near its record.

The honest counterweight

Three things worth holding onto.

One exercise is one exercise. Category A fell to $123,890 in the first August exercise, then rose to $128,501 two weeks later. Premiums move both ways within a quarter, and Category A has now set a new record twice this year, in July and in September.

The supply case is delayed, not disproved. The deregistration wave is already under way. What has held the quota flat is the tapering of LTA's injected certificates, and once that settles, rising deregistrations should start to show.

The next result cannot be reliably forecast. The next exercise opens on 21 September and closes on 23 September. Treat any confident prediction of where it lands with caution.

What to do with it

If you are buying new, the certificate is now a larger share of what you are paying and the Category A saving is close to gone. That is worth reworking rather than assuming.

If you are buying used, this changes the market you are buying in but it does not change which car is right for you. Run the depreciation, which is price minus PARF over the years left on the certificate, and compare that number rather than the monthly.

If you are facing renewal, get the October PQP from OneMotoring, get the ARF from your log card, and do the comparison properly before the deadline rather than in the week before it.