在購買新的車輛之前，在新加坡，潛在的車主都必需要向陸路交通管理局（LTA）先申辦擁車證(Certificate of Entitlement)。
COE Category Refinement in 2013
In September 2013, The COE system has been refined to include a new criterion for Category A cars. Under the change, the engine power of Cat A cars should not exceed 97 kilowatts (kW). This is equivalent to about 130 brake horsepower. This is in addition to the previous criterion of engine capacity of Cat A cars not exceeding 1600 cubic centimetres. However, cars with engine power output exceeding 97 kW will be classified under Category B in COE bidding exercises starting February 2014 despite having engine capacity below 1600 cubic centimetres. The review of the COE categories' criteria was because LTA wanted to differentiate and regulate the buying of mass market and premium cars under Cat A in a bid to control COE prices that hovered closer and closer to S$100,000.
最初，牌照準證(COEs)分成八大類，但該系統現已被簡化為僅僅五個類別。A組、B組、與D組 是不可轉讓的。Taxis used to be classed under category A but issuance of COEs became unrestricted from August 2012 onwards.
Prior to May 1999
|Cat 1||Cars 1000cc & below|
|Cat 2||Cars 1001-1600cc & Taxis|
|Cat 3||Cars 1601-2000cc|
|Cat 4||Cars above 2000cc|
|Cat 5||Goods Vehicles & Buses|
|Cat 7||"Open" (for any kind of vehicle)|
|Cat A||Cars 1600cc & below, and the engine power should not exceed 97 kilowatts (kW)|
|Cat B||Cars 1600cc & above, or the engine power output exceeds 97kW|
|Cat C||Goods Vehicles & Buses|
"Open" (for any kind of vehicle)