I have a friend with a Non-O visa which will expire next month on October 19th 2023. He got the visa last year and would now like to know if he leaves Thailand before his visa expires and reenters Thailand will he automatically get another year on his visa?

A normal non O visa provides a stay of 90 days - a multi entry type can provide such 90 day stays for the one year validity so an entry before it expires would get a new 90 day entry.  Any entry could be extended for a one year stay if conditions are met - and continued each year.

 

Or does you friend have a non immigrant OA visa (pre approved one year stay on entry)?  That only provides the one year stay unless you extend at immigration with financials/medical insurance.  

49 minutes ago, oslooskar said:

I have a friend with a Non-O visa which will expire next month on October 19th 2023

Seems that your friend has a Non O-A.

If that's the case he could exit and reenter prior to expiry of the Non O-A and be stamped in for 12 months provided he has the required insurance for that period. 

 

If he actually has a ME Non O visa valid for 12 months then exit Thailand and reenter prior to expiry he would be given 3 month stamp

10 hours ago, oslooskar said:

I have a friend with a Non-O visa which will expire next month on October 19th 2023. He got the visa last year and would now like to know if he leaves Thailand before his visa expires and reenters Thailand will he automatically get another year on his visa?

There is no way ANYONE can tell you the answer without knowing WHERE he got his "Non-O visa".

If he got it inside the country NO, he doesn't get another year if he exits/re-enters before it expires.

IF on the other hand he got a Non-Immigrant Type OA <- notice the A after the O ???? from the thai consulate in HIS country before he came here, the type of visa that requires mandatory insurance, a medical certificate, proof of funds in his country and he was stamped in for a whole year when he entered thailand he CAN inside bounce out and back (with a new year of the mandatory insurance) and get another year entry stamp

There is a HUGE difference between a Non-O, a Non-OA, and a year extension of stay you get INSIDE the country from a Non-O visa 

What does your "friend" have? post an image of his current stamp if he doesn't know..

Thank you, Gentlemen! My friend has decided that he will simply try to renew his visa here in Thailand.

 

Border runs are more easily done when one is young and in good health. Thanks again for the info.