Why are the letters O and I not used in license plate numbers?
2 Answers
License plate numbers do not include the letters I and O to prevent confusion with the numbers 1 and 0. In China, the use of the letters O and I is not permitted when applying for license plates, so only the numbers 1 and 0 are seen. International context: 1. European Union: In the EU, regardless of the arrangement in different regions, the letter and number sections are separated, so there is no confusion between these numbers and letters. 2. Sweden, Estonia, etc.: Sweden, Estonia, Finland, Hungary, Lithuania, and Belgium all use the combination "ABC123". Norway and Denmark use the combination "AB12345".
License plates avoid using the letters O and I primarily because they can be visually confused with the numbers 0 and 1. Recall the era of old-fashioned license plates when manual recording was common—if a plate contained an O, someone might mistake it for a 0, or an I could be misread as a 1, leading to registration errors or fines. With the rise of automobiles, countries adopted standardized coding, such as international organizations recommending the avoidance of these easily confused letters. Nowadays, when you go to the DMV to get a new plate, O and I are skipped by default and replaced with other letters, significantly reducing errors. I remember seeing a relative get wrongly fined when I was a kid simply because the license plate was misread. Overall, this is the result of long-term historical evolution, ensuring accurate information transmission and improving road traffic efficiency.
