ATP written questions

* Minimum Age 23 to Hold an ATP Rating
* Military experience per FAR 61.73 or Commercial Instrument Certificate
* Current FAA Medical Certificate
* Flight Time per FAR 61.159 Requirements:

1,500 Hours Total Time
500 Hours Cross Country Time
100 Hours Night Time
75 Hours Instrument Time of Actual or Simulated Instrument Time (50 Hours Must be in an Airplane)
250 Hours PIC Airplane
Is their a minimum qualifications for a ATP written licence and is it true you have to be 21?

[/ QUOTE ] To answer your question more specifically... There is no such thing as an "ATP written license", the written allows you to take the practical... I betting you knew that and just misworded it.
Also, there's no "official" rule that says you have to be 21 to take the test... however, the test is only good for two years and you can't take the practical until you are 23... so that's basically a backdoor way of saying you have to be 21 to take the test.

Hope that helps.

Yes, you must be 21 to take the ATP written. There is no endorsement required to take it though.
The official rule is as follows:

61.35 (a)(2)(iii) Date of birth, which shows the applicant meets or will meet the age requirements of this part for the certificate sought before the expiration date of the airman knowledge test report.

So yes, you must be 21 in order to take the ATP written.