What Your Suppliers Need From the Seating Plan
What the venue, the caterer and the stationer actually get from a finished plan, which meals get counted, and the questions worth asking each of them.
At some point the seating plan stops being yours and becomes 3 documents other people work from. The venue sets the room from one, the caterer counts from another, and the stationer prints names from a third. If those 3 disagree, you find out on the day.
This is what each of them is doing with it, and what is worth asking before you send anything.
We cannot tell you what your suppliers require
Worth saying plainly, because plenty of wedding advice will hand you a confident list.
Card sizes, plate counts, notice periods and file formats are set by the individual business you hired, and they vary. We have never seen your caterer's kitchen or your stationer's press. Anything written here as "caterers need X" would be a guess dressed up as a standard, and you would find out it was wrong at the point it mattered.
So what follows is what a seating plan CONTAINS, and the questions that get you their answer rather than ours.
The venue
They are setting a room. What they act on is the shape of it: how many tables, what shape, where they go, and which way the top table faces.
A floor plan they can hold is worth more than a description. Numbered tables matter more than named ones, because on the morning nobody is looking for "Verona".
Worth asking: how late can the layout change, whether the numbers on your plan match the numbers they use, and where the speakers and the accessible toilet are.
The caterer
They are counting plates, and the count has to reconcile to a list of names or somebody goes without.
The thing that goes wrong here is not the total. It is the meals nobody put on the list: the photographer, the band, the videographer, a child on a smaller portion, a carer attending with a guest. Some of those people are at a table, some are not, and some eat at a different time.
Make one list of every person who eats, whether or not they have a seat. That is the number the caterer needs, and it is almost never the same as your guest count.
Dietary requirements need to reach them attached to a seat, not as a separate note. "3 vegetarians" is not actionable at service. "Table 6, seat 2, vegetarian" is.
Worth asking: when they need final numbers, what happens if it moves after that, whether supplier meals are charged differently, and how they want dietary notes laid out.
The stationer
They are printing names, and a name that is wrong is wrong permanently and in public.
They need the names exactly as you want them to read, including the ones you spell differently on purpose. Send the list you actually hold, not a retyped version, because retyping is where the errors come from.
Proof it before it prints, out loud, with somebody who knows the family.
Worth asking: their cut-off, what a reprint costs, and what format they want the list in.
Send the same version to all 3
The most common failure is not a wrong document. It is 3 right documents from different afternoons.
Export them together, on the same day, after the last change you expect to make. If something moves afterwards, resend all 3 rather than the one you think is affected, because the one you think is affected is usually not the only one.
What goes to each of the three is set out in the supplier handover pack.
Suppliers use the words differently, and the difference matters when you are ordering: table plan vs seating chart vs escort cards sets out which is which.