正则表达式前三个字符，然后只有数字或字符，可选地后跟两位数字

Question

I am trying to create a regex that will match first three characters at the beginning, then digits or characters followed by (optionally) one character followed by two digits. The maximum length is 25.

BER12345 - match
BER123456A10 - match

My attempt: ^(?=[AZ]{3,25}$)[A-Z0-9]{5,20}[0-9]{0,2]$

Answer 1

This should do the trick:

(^[AZ]{3}[A-Z0-9]{1,19}[A-Z0-9]\d{2}$)|(^[AZ]{3}[A-Z0-9]{1,22}$) Regex101

BER - no match (desn't have digits or chars after begining)
BER456 - match
BER12345 - match
BER123456A10 - match
BER12345678910dasdd123 - no match (lowercase)
BER1234567890123456789123 - match (only numbers) 
BER1234S67890AFF456789123 - match (uppercase) 
BER1234S67890AFF4567891DA - match (with letters at the end) 
BER12345678989A10dasdd123 - no match (lowercase)
BER1234S67890AFF456789123A - no match (max size)
BER1234567890123456789A10AAA123 - no match (max size)

If you want to match the first example above with only 3 chars BER , just change {1,19} and {1,22} to {0,19} and {0,22}