How do you handle a guest who brings an uninvited plus-one?

Short answer

You handle it by politely asking your guest to leave their uninvited companion behind, or by making a quiet exception if you can. The right approach depends on your venue and your budget.

This is one of the trickiest bits of wedding etiquette, and it happens more often than you might think. Your seating plan, meal count and venue capacity were all set based on the names on your guest list, so an extra person can cause real problems for everyone.

If your budget and venue allow, you can quietly make an exception. But you should do this before the day, not in the car park. If you cannot make room, speak to your guest privately as soon as you know. Do not make a scene in front of other guests.

Here is how to handle it:

Ask the guest to step aside with you and explain that the invitation was for them alone.
Offer to cover the cost of their travel home if they have driven.
If they have already arrived, ask your wedding planner or a trusted friend to help them leave without drawing attention.
If you decide to let them stay, make sure the caterer knows and there is a seat at their table.

Some families feel pressure to be generous, and that is understandable. But your wedding is not the place to rescue strangers or friends you did not invite. A firm but kind conversation now will save a much bigger awkward moment later.