Open the client and use Edit Client. Full steps below.
Where: Clients in the left sidebar
Plans: All plans
Steps
Open the client and use Edit Client.
Switch More details on — it reveals company name, secondary phone, website, preferred contact method, residential or commercial, tags, billing address and notes.
Save. The switch opens by itself next time if any of those fields already hold something.
Rules and limits
The extra fields sit behind the More details switch so the normal form stays short.
Only the addresses saved on that client appear in the send confirmation window.
Still stuck?
If a step does not match what you see on screen, stop there and open a ticket from Support > My Tickets with a screenshot of that step. The team will look at the account directly.