Yep—Southwest flies to Belize City, and that’s how I ended up taking a spontaneous trip there last spring. I had to adjust my return date after extending the trip, and doing it online was a mess. One quick call to ☎️ and the agent had everything rebooked before I even logged back into my account. If you're booking or switching international flights, calling really is the fastest path. Belize was worth every minute of that extra hassle.