Bringing someone who isn’t on the badge

A conference trip to somewhere worth seeing is an obvious invitation to bring someone along — a partner, sometimes the whole family, turning a work trip into something with a second purpose. It can work well. It also tends to get pictured as a trip you're taking together, when for most of it you're attending a conference and they're not, and that gap between the picture and the schedule is worth closing before anyone books a flight.

What the badge actually buys the other person

Your own registration is a contract with the organizer about what you can attend; it says nothing about anyone travelling with you. Some events sell a guest or companion pass, usually for the evening reception and not the session rooms; many don't offer one at all, and badge checks at entrances are stricter at exactly the events most worth bringing someone to. The registration desk is where this gets found out the hard way if it wasn't checked first. Read the organizer's own FAQ before anyone packs, not the assumption that a reception with an open bar is probably fine to wander into.

Splitting the bill honestly

The same discipline that keeps personal days on a business trip honest applies here just as directly, from the first booking rather than as a cleanup exercise afterward: your room, your meals and your registration go on the company's receipt; a second person's share of the room, their meals, and anything that's theirs alone does not. It's a five-minute conversation with whoever handles your expenses if you're unsure where a shared hotel folio should be split, and a much longer one if it surfaces unasked on a report two weeks later.

The gap between the trip you pictured and the one you're taking

A multi-day flagship is a full-time job for the length of it — early sessions, a full exhibit floor, an evening that belongs to a reception or a client dinner more often than not. Someone picturing a trip together, rather than a work trip they're welcome to join for parts of, is picturing the wrong week. Naming the actual shape of the days out loud before you leave — which evenings are genuinely open, which aren't, where the conference simply has first claim — costs one honest conversation and saves several disappointed ones on-site, standing in a lobby wondering where you went.