Are all ZIP codes 5 digits?

Related questions

1. How does the UK postcode system work?
2. What is a postcode district?
3. Can postcodes change?
4. Why do postcodes change?
5. How are postcodes decided?
6. Is your postcode unique to your house?
7. What is the biggest postcode area?
8. What do the letters in a postcode mean?
9. What does my postcode mean?
10. Is zip code and PIN code same?

Tags

1. #introduced
2. #additional
3. #first
4. #codes
5. #basic
6. #stands
7. #refer
8. #later
9. #still
10. #precisely
11. #extended
12. #delivery
13. #format
14. #improvement
15. #digit
16. #digits
17. #postal
18. #group
19. #after