One record per phone number, however many lists that person is on — what a contact holds, and what changes when you edit or remove one.
A list decides who a message reaches. A contact is who they are. Somebody can be on your Wardens list, your First Aiders list and your All Staff list, and they are still one contact — one name, one set of details, one record of whether they want to hear from you.
That matters because it decides where a change lands. Editing a contact changes them everywhere at once. Taking somebody off a list only takes them off that list; they stay a contact, and stay on every other list they are on.
Contacts live under Recipients → Contacts. The search box matches on number, name or your own reference, so any of these finds the same person:
07911 123456 the number as somebody would write it
+447911123456 the same number in full international form
Ada Lovelace their name
S1049823 your own reference for themThe filter beside it narrows to people you can reach, people who have opted out, or contacts that have been removed. That middle one is worth looking at now and again: it is the count of people you hold a number for and cannot warn.
Use Add contact for one person. The number is checked as you type, so if you already hold it you are told straight away — along with their name and which lists they are on — rather than finding out when the save fails.
Click any row in the contact list to open it. The dialog names the lists they are on, because a change here follows them onto all of those lists — that is the point of holding the person once rather than once per list.
Where one of your fields has a default value, the editor says what a message will fall back to if you leave it empty:
Field: Tutor
Default: your course leader
Left empty, a message saying "Your tutor is {{tutor}}."
reaches them as "Your tutor is your course leader."You cannot type a new number over an old one, because that would be indistinguishable from a different person. Instead, import a file that carries your reference for them alongside the new number. Because the reference matches, the import treats it as a change of handset and moves the existing contact — so they keep their lists, their details and their opt-out status.
Remove contact in the contact dialog takes them off every list they are on and deletes their details. It does not recall anything already sent.
There is one exception, and it is deliberate. If the person has opted out, removing them keeps the number and the fact that they opted out. Everything describing them — name, your fields, email, your reference — is deleted, and what remains is a record that this number asked not to be contacted.
Removed contacts are out of the contact list unless you choose Removed in the filter. If somebody is later added back to a list — by import, by hand or by signing up — the contact comes back, and their opt-out comes back with it.
Opting out belongs to the person, not to a list. Someone who replies STOP is opted out across your whole workspace, and any list they are added to afterwards inherits that — you cannot re-subscribe somebody by adding them to a new list, or by importing them again.
They are still shown on the lists they belong to, marked as opted out, rather than quietly vanishing. A roster that silently loses people is worse than one that tells you who it cannot reach.
Contacts belong to your workspace and nothing crosses that boundary. If somebody is a contact of two organisations using the service, each holds their own record with their own name, fields and consent, and neither can see the other. Somebody opting out of your messages does not opt them out of anybody else's.