Every small school has one. The teacher parents request by name, whose classes fill first, who gets mentioned in every referral.
They are your strongest asset. They are also the thing most likely to take twenty students out of the door in a single month, and the risk grows quietly the more successful they are.
Work out how exposed you actually are
Count the students enrolled in that teacher's classes as a share of total enrolment. Then ask the harder question: how many of those families chose the school, and how many chose that person?
You can approximate it. Look at who enrolled after a trial with them specifically, and who asks for them by name at renewal. If the number is above about a fifth of your revenue, you have a single point of failure that no software and no process will cover.
Spread the relationship without diminishing anyone
The instinct — quietly move students to other teachers — is transparent to parents and insulting to the teacher. It creates the resignation it was meant to prevent.
What works is making the school visible alongside the person:
- Two names on every class. A regular assistant or co-teacher who parents actually meet, so continuity has a face.
- Their methods written down. Not surveillance: the level maps, the lesson structures, the things they do that work. Ask them to author it, credit them for it, and pay for the time. A teacher asked to document their craft as an expert responds very differently from one who senses they are being made replaceable.
- Progress reports come from the school. Same format across every teacher, so the quality parents perceive attaches to your name too.
Pay them like the asset they are, before they ask
The market rate for your best teacher is not what you are currently paying. Somebody will eventually tell them so.
A raise you offer unprompted costs the same money and buys something a counter-offer never does. By the time they are negotiating, they have already had the conversation with somebody else.
The cheapest retention you will ever do is the raise nobody had to ask for.
Plan for it anyway
Even done well, people leave — for a partner's job, a different country, a career change that has nothing to do with you. When a teacher resigns mid-term covers the first 48 hours, which decide how many families you keep.