A chat thread works until one person writes “probably medium,” another changes their mind, and the organizer must reconstruct the latest answer. The fix is not a larger form; it is a smaller, shared contract.
Start with one exact garment
Write the item clearly enough that nobody confuses a unisex event shirt with a fitted staff polo. Add the vendor or style note when the distinction matters, then keep color, payment, delivery, and design outside the size question.
Collect one explicit choice
Share the response link in the channel the group already uses. Ask for a recognizable name and exactly one supplied label. Duplicate names are acceptable; the organizer sees separate responses and should not treat the name as verified identity.
Let corrections travel with the participant
After submission, the participant saves a private receipt. A late correction or withdrawal no longer requires another chat message, and the manager’s count changes with the current active response instead of accumulating contradictory replies.