Zip's Mailbox Club › The Wonder Library
Published August 27, 2026
A letter for a child's first lost tooth is a short note left under the pillow or posted the next morning, written either as the Tooth Fairy or plainly as a grown-up, marking the day a child's face started to change. Write five things and stop: the date, the child's name spelled out, one specific detail only somebody who was there could know, one line about the tooth itself and where it goes now, and one small instruction for the next one.
That is the whole method. Everything below is the detail: whether the letter should come from the Tooth Fairy or from you, what changes at four, at six, at nine, the lines to borrow when you are writing at eleven at night, the four sentences that turn a piece of magic into a dental lecture, and what to do with the tooth once the letter is written. This page is the wobbly-tooth chapter of our broader guide to milestone letters for kids, which also covers birthdays, first days of school, hard weeks, and new siblings.
It is not really about the tooth. It is the first time most children get post that is unmistakably theirs.
A lost tooth is one of the earliest events in a childhood that a child understands as happening to them personally rather than to the family. Nobody else in the house lost it. It hurt a bit, it was strange, and it is visible in the mirror. That combination is why the letter works: there is already a strong feeling looking for something to attach itself to, and a small piece of paper with their name on it is a very good hook.
It also does a quieter job. A first tooth is a child's earliest experience of a body change that cannot be undone, and some children find that genuinely unsettling rather than exciting. A letter that names the change calmly, says it is supposed to happen, and treats it as an occasion rather than a loss is doing more work than it appears to be doing.
When you are writing it late at night with the tooth in a tissue on the counter, write these five and put the pen down.
Five sentences is a complete letter here. It is also more likely to be kept than a long one, because the object is the point and a small note is easier to keep than a page.
Either. They do different jobs, and there is no reason a family cannot do both.
The Tooth Fairy letter is theatre. It is short, slightly odd, written in handwriting the child does not recognise, and it usually arrives under the pillow overnight. Its job is to explain where the tooth went and to make the morning strange in a good way. Keep it under six sentences, use small paper, and resist explaining too much: the appeal of the Tooth Fairy is that she is not fully accounted for.
The grown-up letter is a keepsake. It says, in your own name, this is the day your face started changing, here is exactly what you were like, and here is what I thought watching it happen. It works whether or not your family does the Tooth Fairy at all, and it is the one that survives the year the child works out who has been leaving the coins.
If you are choosing only one and the child is under six, write the fairy. If the child is seven or older, or already sceptical, write the second kind and post it properly, which is a better fit for that age anyway. The same split shows up in our guide to a birthday letter to your child, where the ceremony version and the keepsake version also pull in different directions.
The five-part shape does not change. What changes is how much explanation a child wants and what counts as a reply.
An early loser is often more alarmed than delighted, so lead with the reassurance and let the magic come second. Say plainly that this is supposed to happen, that a new one is already on its way, and that it will not hurt for long. Keep it to two or three short lines in large writing, draw the tooth instead of describing it, and read it aloud rather than expecting them to read it. Leave a blank space at the bottom, because a drawing is a complete reply at this age. Our guide to mail for 4 year olds covers what a pre-reader actually does with a letter.
This is the main event, and the age most first-tooth letters are written for. Five and six year olds are literal, competitive about being first, and extremely interested in procedure, so tell them the procedure: what happens to the tooth, whether the next one has a schedule, what the rules are. Write slightly below their reading level so they can get through it alone, because doing that is half the pleasure. End with a question they can answer in one sentence. See mail for 5 year olds and mail for 6 year olds for what lands in this band.
Old enough to be testing the story, and many are. Do not over-defend it. A letter at this age can be affectionate and slightly knowing, and the child gets to decide how much they believe, which is usually what they want. A late first tooth also carries a year of waiting behind it, so name the wait rather than skipping past it. If they are writing anything back, helping your kid write their first letter is a useful companion.
By ten the remaining teeth come out with no ceremony at all, and the letter that still matters is retrospective: the one written back at five or six and kept. If you are only starting now, skip the fairy entirely and write a plain, dry, unsentimental letter about the whole run of them. Older children are embarrassed by performed sweetness and disarmed by specifics, so let the details carry it.
Starting lines, not templates. Pick one, finish it with something true, and the rest usually arrives.
A longer bank of starting lines lives in our letter-writing prompts for kids, which works just as well for an adult staring at a blank page at midnight.
Four sentences that appear in a great many tooth letters and should not.
There is a fifth, subtler one: writing far too much. A page of careful prose signed by a fairy is the fastest way to break the illusion, because the whole premise is that something very small wrote it in a hurry.
Decide before you write, because the letter has to say something about it and children hold you to the answer.
The workable options are few. Keep it in a labelled box or envelope, which most families do and which is the reason so many drawers contain an unmarked tooth nobody can date. Take it and say so, if the fairy story is doing the work in your house. Or hand it straight back, which some children strongly prefer and which is a perfectly good ending. What causes trouble is having no answer, or a different answer next time. If you keep it, write the date on the envelope in the same moment you write the letter, and you will have solved the mystery tooth problem for good.
Under the pillow is the tradition, and it is a good one. But there is a specific case for putting the second letter in the mail.
A pillow letter is found in a private, sleepy moment and is usually read once. A letter that arrives days later in an envelope with the child's name and address on it is a different object entirely. It is proof that the event travelled outside the house, that somewhere in the world a record exists of the day the tooth came out. That is a surprisingly large idea for a five year old, and it is the reason grandparents who post one are remembered for it.
Mail also does two things a pillow note cannot: it survives, because envelopes get kept and loose notes get lost, and it can be timed, so the ceremony does not have to end the next morning. Our guide to why kids still love getting real mail covers the wider version of this.
The best outcome of a first-tooth letter is a reply, and this is one of the few occasions where a young child genuinely wants to write one.
There is a question they want answered, which makes writing easy: what do you do with all the teeth, where do you live, will you come back. The answer they send can be a scribble at four, a drawing of a gap-toothed face at six, a demanding paragraph at eight. What keeps a child writing is being remembered. A child who asks a question and gets it answered by name learns that writing reaches a person; a child whose letter disappears into silence stops writing, usually for good. That argument, at length, is in what happens when your child writes back. If the writing itself is the struggle, how to encourage a reluctant writer is the better place to start.
The tooth letter is one only you can write. Nobody else knows about the apple.
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Write five things and stop: the date, the child's name spelled out, one specific detail only somebody who was there could know, one line about the tooth itself and where it goes now, and one small instruction for the next one. The detail is the part that does the work. A child who has just lost a tooth is watching closely to see whether the letter is generic, and a sentence naming the apple, the wobble at dinner, or the exact tooth that came out is the thing that makes the letter feel addressed to them rather than to any six year old.
Either works, and the two do different jobs, so some families write both. A Tooth Fairy letter is a piece of theatre: it is short, it is a bit strange, it explains where the tooth went, and it usually turns up under the pillow. A letter from a parent or a grandparent is a keepsake: it says this is the day your face started changing and here is what you were like when it happened, and it survives long past the age of believing in fairies. If your family does not do the Tooth Fairy at all, the second kind stands perfectly well on its own.
Most children lose the first one somewhere between five and seven, usually a bottom front tooth, and anywhere from about four to eight is ordinary. That spread is worth knowing before you write, because the letter for a four year old and the letter for an eight year old are different letters. Early losers often need reassurance more than ceremony, since a tooth falling out is alarming when nobody in the class has done it yet. Late losers have usually spent a year watching everybody else get a visit, so name the wait rather than pretending it did not happen.
There is no correct amount, and the only rule that matters is picking a number you are willing to repeat about nineteen more times. Children keep score across siblings and across years, so a generous first tooth quietly sets the price of every tooth after it. Some families give a coin, some give a note, some give no money at all and give a book or a small ceremony instead. If you want the letter rather than the money to be the memorable part, keep the amount modest and put the effort into the writing.
Short. Four to six sentences on a small piece of paper is a complete letter, and small paper helps, because a tiny note reads as though it came from somebody tiny. Length works against you here in a way it does not in other letters: the charm of this one is that it is a strange little object that appeared overnight, and a full page of prose breaks the spell. If you have more to say, say it in the parent letter, which can be as long as you like because nobody is pretending a fairy wrote it.
Leave out four things: a scolding about brushing, a comparison to a sibling's teeth, a promise about when the next tooth will come out, and anything that sounds like an adult wrote it in a hurry. The brushing lecture is the most common mistake, and it turns a piece of magic into a dental appointment. A promise about timing is one you cannot keep, since teeth arrive on their own schedule. And skip the handwriting you use for shopping lists, because children recognise a parent's writing far earlier than parents expect.
Yes, and for a pre-reader the object matters more than the words. A four or five year old takes in the small folded paper, their own name on the front, and a grown-up reading it out loud in a slightly different voice, and that is the whole event. Keep it to two or three concrete lines, draw the tooth rather than describing it, and leave a blank space at the bottom, because a drawing is a complete reply at that age. Pre-readers also ask for the same letter to be read again for weeks, which is their version of rereading it.
Every letter comes from Zip. Zip reads every letter a child sends back, and Zip always writes back — so the next letter picks up where they left off. Behind the scenes, Zip's Mailbox Club was founded by Mack, a dad who writes, personalizes, and hand-packs the mail behind these guides. Read the founder story →
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