A last-minute plus-one does not automatically mean a new seating chart
First confirm the extra person is attending and included in the venue and catering arrangements. Then find a change that keeps the new guest with their partner and respects the seating decisions you already made. Do not assume an eight-seat table can take nine.
One new guest, one existing guest moved
| Table | Before | After | What changed |
|---|---|---|---|
| A | 8 | 8 | Jordan joins; Pat moves to B |
| B | 7 | 8 | Pat joins |
| C | 8 | 8 | Nothing |
| Total | 23 | 24 | One additional guest |
The after assignment
| Table | Capacity | Guests |
|---|---|---|
| A | 8 | Alex, Jordan, A1, A2, A3, A4, A5, A6 |
| B | 8 | Pat, B1, B2, B3, B4, B5, B6, B7 |
| C | 8 | C1, C2, C3, C4, C5, C6, C7, C8 |
Synthetic. One existing guest, Pat, changes tables. The other 22 existing guests stay. Not a live solver result, and not a promise that every plus-one takes one move.
What the check covers
Everyone on the after list appears once. No table exceeds eight. Alex and Jordan share a table. The declared keep-apart between A1 and B1 still holds.
Count changed assignments among existing guests separately from the new guest. Here, one existing guest moves.
When that one-person fix does not work
Pat may need to stay with a partner. The spare seat may be at a table Pat cannot join. The only spare capacity may be in the wrong place for an intact family.
Those are reasons to test another assignment, not to override the constraint. If nothing fits, change an explicit assumption: confirmed capacity, table count, a genuinely optional preference, or the guest list.
Related
Synthetic. One existing guest, Pat, changes tables. The other 22 existing guests stay. Not a live solver result, and not a promise that every plus-one takes one move.
About 10 minutes. Software, not a waitlist — your chart tonight.