A wedding party books forty rooms and the details move every week

A group booking is not a booking; it is a negotiation that continues until the event. Rooms change, meal counts change, arrival times change, and each change arrives through whichever channel the organiser finds convenient.

Where it breaks

The kitchen prepares for the count it was given. Housekeeping prepares the rooms it was told about. If either is working from a superseded version, the failure is visible to the guest and is attributed to the hotel's competence rather than to its record-keeping.

Dated changes, not overwrites

The billing argument at the end is always about what was agreed and when. A record that overwrites keeps only the latest position; one that keeps the sequence can settle the question in seconds.

The organiser benefits too

Sending back a written confirmation after each change is the single most effective thing a hotel can do on group business. It converts a series of phone calls into an agreed document, and organisers generally welcome it because they are managing the same confusion from their side.