Adding an entry in /etc/sudoers

This should be pretty straight forward, but I haven't messed with the /etc/sudoers in some time and can't quite seem to get my syntax correct.

I have created a vendor account that needs to be able to sudo to a service account.

I started with some user alias configs, but here is where I am now.

vendor ALL=(service) NOPASSWD: /bin/su

Sorry, user vendor is not allowed to execute '/bin/su - service' as root on

Been awhile and don't do a lot with this. Probably something obvious, that I am just not seeing.

Thanks