How to read SIPP codes for car categories?
SIPP codes (Standard Interline Passenger Procedure) are 4-letter industry codes used by car rental companies to describe the key features of a vehicle category. Rather than guaranteeing a specific car brand, these codes make it easy to compare vehicle characteristics—such as size, transmission, and air conditioning—across different suppliers.
Each of the 4 letters in a SIPP code represents a specific vehicle characteristic:
M = Mini
E = Economy
C = Compact
S = Standard
F = Full-size
L = Luxury
B = 2/3 Doors
D = 4/5 Doors
W = Wagon/Estate
V = Passenger Van
S = SUV
M = Manual
A = Automatic
N = Manual 4WD
B = Automatic 4WD
R = Air Conditioning included
N = No Air Conditioning
Example - If your voucher shows CDMR, it means:
C = Compact
D = 4/5 Doors
M = Manual Transmission
R = Air Conditioning included
"I booked a 'VW Golf', so the supplier will hand me the keys to a VW Golf."
You actually booked a CDMR class vehicle (Compact, 4-Door, Manual, A/C). The VW Golf shown during booking is an example of the vehicle category. You may receive another similar model, such as a Ford Focus, Opel Astra, or Peugeot 308. All of these vehicles share the same SIPP classification and features.
"I booked an SUV, so it will definitely have 4-wheel drive for the mountains."
Not all SUVs are 4x4! SUVs can be either 2-wheel drive or 4-wheel drive.
The 3rd letter of the SIPP code indicates the drivetrain:
If the code shows M or A, it refers to a standard 2-wheel drive vehicle.
If it shows N or B, the vehicle includes 4-wheel drive.
You must specifically look for an "N" or "B" for guaranteed 4-wheel drive.
💡 Did You Know?
To keep things simple, our website translates these industry SIPP codes into clear, everyday descriptions. You can filter cars by features like Automatic transmission or 4x4 without needing to remember the four-letter code.
What To Do Next:
Check the vehicle features listed on your voucher or the search results page to confirm the specifications. If you specifically need an automatic transmission, make sure it clearly says “Automatic” (or the 3rd letter of the SIPP code is “A”).
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