What is your best tip for handling late RSVP responders after your caterer’s final headcount deadline has already passed?

What is your best tip for handling late RSVP responders after your caterer’s final headcount deadline has already passed? Following up on my own post — here is what our caterer and coordinator told us, and it worked:

• Call the caterer before you say no to anyone. Most can add 5–10 heads up to 72 hours out, sometimes with a small per-plate surcharge. Ours added eight people for $22 each.
• Keep a two-tier guest mental list: people you would genuinely make room for (family, wedding party plus-ones) versus people you can gently tell "we already submitted final numbers, we are so sorry."
• Meal choice defaults to the most common entree for anyone added late. No re-opening the whole menu.
• Next time, set your RSVP deadline two weeks BEFORE the caterer's deadline. The gap is your chasing window and it is the single best trick our planner gave us.

Eleven late yeses felt like a crisis. It was one phone call and $176.