It depends on your venue. Most residential properties (backyards, private homes) don't require one, since you're serving your own guests, not the public, and not selling drinks. Public venues, ticketed events, or anywhere alcohol might be considered "sold" can require a Special Occasions Permit (SOP) in Alberta. Securing any required license is the client's responsibility, but we're happy to point you in the right direction if you're not sure where your event falls.
Note: liquor licensing and our own liability coverage are two separate things — having the right permit doesn't automatically extend our insurance, and vice versa. Worth asking us directly if your event has any unusual circumstances.