Clients you'd rather not rebook
Two levels of restriction for repeat no-shows, set per client without changing anything for everyone else.
Most salons don't want a salon-wide deposit — they want one for the three people who keep not turning up. That's what the client list restrictions are for.
Two levels
Reach for deposit-required first. It solves the actual problem — an unheld slot — without ending the relationship.
How someone is matched
An entry names a person by email or by phone number. Both are matched forgivingly enough to survive how people actually type: capital letters in an email don't matter, and a phone number matches whether it was entered with brackets, dashes, spaces, or a country code.
A restriction stops someone booking themselves on your page. It doesn't stop you booking them at the desk — that's your call to make in the room, not a rule to enforce against you.
Where it lives
Settings → Client list (opens in a new tab), or from the client's own card. Setting it from the card is usually what you want, because that's where you're standing when you decide.
Say something first
A client who finds out they have been restricted by hitting it on your booking page will assume it's a bug and message you about it. One sentence in advance — that after two missed appointments you now take a deposit — converts an argument into a booking.