If you're flying around Europe, especially to the UK, make sure you know where the lounge is -- many of them are before passport control, and you might not be allowed back through to go to the lounge.
It's all because of the Schengen system, where most of continental Europe has open internal borders and flights are treated as domestic rather than international.
As a result, the business lounges are usually in the "domestic/Schengen" side of the airport, before passport control -- and even sometimes before security.
That makes sense flying between Germany and Italy, where there are no passport checks required, but it's problematic if you're heading between France and the UK, say.
If your brain is on autopilot and you pass the official border at passport control, many countries prevent you from retracing your steps back "into their country" and into the lounge.
Added to the complications if you're flying around Europe, it's fairly common for airlines to contract out their airport staff to a local third party, who sometimes don't speak English confidently enough to explain things to travellers (or, frustratingly frequently, just can't be bothered).
So double-check where the lounge is in the airport. It's often useful to ask which gate it's near, so you have a rough idea where you're heading and how long it'll take to get there.
And make sure you ask how long it should take between the lounge and your gate: since you'll have to get through passport control, you need to leave enough time for the walk, which can be a fair distance.
Do you fly frequently overseas? What's your best tip for your fellow travellers, or the hard-earned knowledge nobody ever thinks to ask about? Share your thoughts with other AusBT readers in a comment below!
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About John Walton
Aviation journalist and travel columnist John took his first long-haul flight when he was eight weeks old and hasn't looked back since. Well, except when facing rearwards in business class.