Birmingham's compact airport rarely appears on premium transatlantic route maps, which is precisely why savvy travelers should know: there's no nonstop business class from Fort Lauderdale to Birmingham, and building an itinerary through the right US hub makes all the difference. American, Delta, and United each offer viable connections—American via Philadelphia or Charlotte using its Flagship Business cabin on the transatlantic legs, Delta routing through JFK or Atlanta into its Delta One suites (increasingly the Airbus A330-900 or A350 configuration on the widebody segment), and United typically funneling through Newark or Washington Dulles aboard its Polaris business seats. The actual FLL-to-hub segment is domestic first class rather than international product, so the real premium experience begins once you're on the widebody transatlantic leg.
Having routed through all three combinations repeatedly, I'd steer most travelers toward Delta via JFK when schedules align—Delta One's suite with closing door offers genuine privacy for the roughly eight-hour block time once you factor in the transatlantic hop, and JFK's Terminal 4 has matured into a smoother connection point than it once was. United's Polaris seats via Newark are nearly as good, and Dulles connections tend to have more breathing room between flights, which matters if your FLL departure runs late during South Florida's summer thunderstorm season. My insider tip: fly the FLL-to-hub segment as early in the day as possible, particularly January through March, since afternoon storms build reliably in Florida even in winter months and can cascade into missed transatlantic connections—an 8 or 9 a.m. departure from FLL gives you a comfortable buffer.
January, February, March, October, and November consistently offer the softest business class fares on this corridor, as both leisure demand to the UK Midlands and business travel dip outside summer and December holiday peaks. Given the routing complexity and fare volatility across three carriers and multiple hub options, setting fare alerts for this specific city pair is far more efficient than manually checking each airline's site—automated tracking will catch the fleeting premium fare drops before they disappear.