CateringGuy.com is in New York City, so i can speak to you about the local laws. New York State does not allow the serving of Alcohol without a permit/license. (period).
If you want to sell liquor, it must be sold with food, and you must have an existing on-premise license in order to file for an "off premise extension". However, with that
said, you can file for a ONE DAY PERMIT for Beer and Wine only (takes about 4 weeks and fees apply). If your Client is seeking "Spirits" or hard liquor then i can only recommend you find or partner with an establishment
that has a on-premise license and is willing to extend this off premise for you and your clients, simply by profit sharing from what is sold by the bar.
Some of our clients include event planners, party promoters, etc. and they all need to "partner" with someone in order to have this Law covered. Sponsors usually will request
for two things, the Permit and the Liability coverage, they are two separate requirements and bartenders who take a bar tending course, do not qualify as "licensed", they are
merely servers with knowledge on drink mixing and rules of serving to legal aged guests etc.
FYI: the NYS ABC states if they provide you a permit for Beer and Wine, then that is all you are allowed to serve at the venue, it is considered illegal to bring in retail hard liquor
and serve it, regardless if you charge for it. Once you file for this permit, and it is detailed, you are putting the spot light on your event, so don't risk the fines and trouble you
will be in if you get caught.
Be smart, find a Partner who has all these bases covered, and i am sure they will enjoy the additional profits while allowing you to make some as well.
hope this helps, CateringGuy