Why spreadsheets become fragile
Spreadsheets work for small events, but as replies arrive across channels they become difficult to reconcile and audit.
Keep status categories explicit
Track three states for every guest: accepted, declined, and pending. Any missing state should be treated as pending until confirmed.
Tie every response to a guest identity
When responses come from message threads, names can be ambiguous. A private RSVP link solves that by attaching each response to one guest record.
Run reminders as a queue
Treat reminder sending as a queue: collect pending guests, send reminders, then re-check status changes in one pass.
Keep a timestamped export
Capture an export snapshot whenever a major vendor deadline approaches so you can reconcile changes after the handoff.