Singapore doesn't print COEs. It recycles them. A vehicle de-registers, the slot is recorded in LTA's forecast, and roughly a year later that same slot reappears as a new COE in a bidding exercise. The chart below shows the supply pipeline in action since 2005.
When a vehicle's ten-year COE expires, the owner has a choice: pay a Prevailing Quota Premium to extend the COE for another five or ten years, or de-register the vehicle and free up its slot.
LTA tracks de-registrations in the forecast year, sets the following year's quota accordingly, and splits it across the twenty-four bidding exercises that make up a COE year. That's the direct mechanical link between the de-registration chart above and the bidding premiums you see on the homepage.
Quota injections (like the Feb 2025 release of 20,000 COEs spread over five years) sit on top of this baseline, which is why annual quota releases can briefly exceed the prior year's de-registrations.