Identify the equipment first
Bring the model information from your manual or a label visible from the floor. Similar-looking remotes are not necessarily compatible with the same opener.
Explain which control is affected
If the wall control works but a handheld remote does not, say so. If nothing responds, opener service may be the better starting point.
Review old access when needed
For a lost remote or a change of occupants, ask how stored controls are managed on your model. Discuss the remotes you want to keep before changing access settings.