Your event is still weeks away, but a guest can no longer book through the group link. The room block may have reached its release date. That deadline belongs in the guest communication as clearly as the date of the event itself.
A block reserves an agreed allocation under particular terms. At the cut-off, the hotel may return unbooked rooms to general inventory. Marriott’s event-planning glossary makes an important distinction: releasing rooms does not necessarily release the organiser from liability for the block.
Three dates that can be different
The block release date, an individual guest’s cancellation deadline and the organiser’s contractual deadlines are separate matters. Do not replace all three with one line saying “book by Friday”. A guest who books before Friday may still have a cancellation policy of their own.
Ask the hotel what happens after the cut-off: can it still offer the group rate if rooms remain, must guests pay the prevailing rate, or is the booking link closed altogether? A Marriott site-inspection checklist explicitly includes whether rates remain available after cut-off, illustrating why this is a question rather than an assumption.
Write a message guests can act on
A useful fictional notice would say: “The group allocation closes at the hotel’s stated local time on 12 May. Use the booking link before then. Later requests depend on availability and the hotel’s rate terms.” Replace the example with the exact deadline and conditions you have confirmed.
Include the hotel’s contact route for accessibility requirements or room questions. Avoid collecting guests’ payment details yourself when the hotel provides a secure booking method.
Check the organiser’s side separately
Review the agreement’s room-night commitment, attrition provisions, deposits and amendment process. If fewer guests are booking than expected, discuss options before the relevant deadline and obtain changes in writing. The hotel’s release of stock and your financial obligations need not move together.
For a guest arriving late to the plan, the practical next step is to ask the hotel what is available now. A screenshot of the original group offer does not by itself reserve a room.