Summary
This page explains what happens when the signal drops during a visit. You can carry on with the appointment. Merlin Mobile keeps the work on the device and uploads it when you are back online.
Details
Merlin Mobile can still be used in areas with poor or limited signal, so users can continue working without interruption. The banner will change from blue to black, and an offline icon is shown, indicating you are currently offline. A message tells you that you are offline. Merlin Mobile keeps the work on the device and uploads it when you are back online. Anything waiting to upload is listed at the top of the screen as a pending item. A new booking, a finished appointment, or another action that could not be sent yet appears there.
If you are booking a follow up appointment, the booking waits at the top of the screen until you are back online.

If the phone switches off
Work already stored on the device is still there when you switch it back on, including after the battery has run out. Sign in again in the same browser on the same phone.
That work stays until it uploads, or until the browser data for Merlin Mobile is cleared. Clear the browser data only after the pending list is empty. Clearing it before then removes the work that has not yet reached Merlin.
Merlin on the desktop is the record once the upload has succeeded. Nothing else keeps a separate copy.