I'm not sure that's correct. The pluralization is for licenses not on-premise. E...

grzm · on Feb 11, 2017

Premises (singular) is a location. He was on the premises.

https://www.merriam-webster.com/dictionary/on%20premises

Premise (singular) is a presupposition. The premise is that we can get this done in 3 weeks.

https://www.merriam-webster.com/dictionary/premise

I agree, it sounds weird. I'd avoid it all together and use on-site.

Edit to add: or, as uncle-comment (?) pointed out with the Wikipedia article, on-premises software is a thing. On-prem might be a good compromise, depending on your penchant for shortening like that.

WildUtah · on Feb 12, 2017

Either way "on-premises licenses" sounds weird so I'm likely to stick with "on-premise licenses" regardless. Sorry.

Downvoted for expressing contempt for the English language and common decency, but then failing to add in the obvious "irregardless."