Breaking the Code

When you reserve a rental car or book airfare, cruises, or hotels, there's software on the back end that takes the information you requested and puts it into a specific format all major global travel providers are able to recognize. We talked about how the vehicle you reserve has standardized codes from a trade organization called ACRISS where every car can be represented in four characters - for instance, a standard convertible with automatic transmission and air conditioning gets converted to "STAR": S - standard, T - convertible, A - automatic transmission, R - air conditioning.

The rental car companies themselves have their own two-character codes embedded in the background when a renter books a car. And given each rental car company's code has to be unique, an oddity arises in naming protocol -- small companies tend to have intuitive codes while major companies do not! While there's no need to know your favorite rental car company's two-character code, there are a few instances where those codes leak out on documents you might see; these come up periodically in emails to our support line (usually with Hertz and Sixt).

Why do Sixt discount codes start with "SX"?

SX is the two-character provider code for Sixt. One would think that Sixt wouldn't have to announce to themselves that a coupon issued by Sixt is a Sixt coupon. Then again, Sixt is a German firm and Germans have their own turns of phrase, such as "Professor Doctor".


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Why are Hertz Gold Plus Rewards called "ZE1"?

This is one of the examples many renters can quickly see. Those who elect to earn points in the Gold Plus Rewards program (rather than frequent flyer miles or hotel points) will see the frequent traveler code of ZE1 on their receipts. The ZE1 code has two nods to Hertz history -- "ZE" is the two-character provider code for Hertz and the "1" is a remnant from when the Hertz program was called "#1 Club Gold"!

And that's not the only Hertz use of their ZE code of note -- rent a car in Europe and the fine print might say "Hertz is partnering with ZE to fill your reservation". There's no reason to worry that Hertz is sending you to some ill-fated subsidiary like Firefly; that's just Hertz being Hertz, "partnering" with themselves.

Most Rental Car Codes are Not Intuitive

Aside from Sixt and SX, most major rental car chain codes are not intuitive. Surprisingly, the easiest to guess codes tend to be with smaller, discount chains! Ready to try some code matching? Here are 15 chains and 15 codes -- no prizes (aside from a sense of personal accomplishment) are available but the answers will be posted tomorrow.

Here's a little Final Jeopardy theme music to help the thought process along.

Match the Rental Car Company ...

  • 1. ACE 
  • 2. Advantage
  • 3. Alamo
  • 4. Avis 
  • 5. Budget 
  • 6. Dollar 
  • 7. Enterprise 
  • 8. Europcar 
  • 9. EZ Rent A Car 
  • 10. Fox 
  • 11. Hertz 
  • 12. National 
  • 13. SilverCar
  • 14. Sixt 
  • 15. Thrifty 

And the Appropriate Vendor Code

  • A. AC
  • B. AD
  • C. AL
  • D. EP
  • E. ET
  • F. EZ
  • G. FX
  • H. SC
  • I. SX
  • J. ZD
  • K. ZE
  • L. ZI
  • M. ZL
  • N. ZR
  • O. ZT

Yes, six of those 15 companies have character codes that start with "Z"! Answers? Those will be in Part II (tomorrow). And fortunately, you don't need to know these codes to request quotes and book the cheapest possible rates on your reservations! All that's needed to get the cheapest rates on rental cars is to click below to request quotes -- we'll then send out the lowest possible rates within minutes.

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