Getting started
# iMessage link button
A link that opens Messages with your number in the To field and a sentence already typed. The customer taps send. That is the whole mechanism — no SDK, no script, one anchor tag.
## Why you want them to text first
Two things happen the moment a customer sends you the first message, and both of them matter more than the button itself.
**You can reply as much as the conversation needs.** An inbound message opens a conversation the customer started. Replying inside one is not outreach, and is not rate limited the way a cold first message to a stranger is. The whole shape of a healthy line is: they start it, you answer it.
**Your number is now in their phone.** A thread they began sits in their Messages list with everything else they care about. Your next message arrives in a conversation they recognise instead of as an unknown number — which is the difference between being read and being reported.
## The link
Your number in E.164, then the message you want typed for them.
```
Text us
```
## The `?&` is not a typo
Android follows RFC 5724 and expects `?body=`. iOS has always expected `&body=`. Writing `?&body=` satisfies both: Android reads the `?` and an empty first parameter, iOS reads the `&`.
It is a convention rather than a standard, and it is the one that works on the two platforms your customers actually hold. Pick either official form instead and the prefilled text silently vanishes for half of them — silently being the problem, since the link still opens and still looks like it worked.
## Encoding the body
Run it through `encodeURIComponent`. An apostrophe, an ampersand or a line break left raw will truncate the message at that character or break the link outright.
```
const number = "+16465550142";
const text = "Hi, I'd like to book a quote";
const href = `sms:${number}?&body=${encodeURIComponent(text)}`;
```
## Where it will not work
Desktop Windows and Linux browsers have no handler for `sms:` and do nothing at all — no error, no dialog. In-app browsers inside X, Instagram and TikTok may refuse the hand-off to Messages even on a phone that would otherwise manage it.
So show the number as text beside the button, not only inside it. A customer on a laptop can still read it and pick up their phone; a customer whose tap did nothing has something to fall back on. It costs one line and it is the difference between a dead button and a slightly slower path.
```
Text us
or text (646) 555-0142
```
## Apple's position on the body
Apple's archived URL scheme reference says an `sms:` URL must not include a body. Every shipping version of iOS has honoured one anyway, and the whole industry depends on it. Treat it as stable in practice rather than guaranteed: the link must still be worth tapping if the text never appears, which is another reason the button says *Text us* rather than *Send this message*.
## Generating one
The console builds the link for any number on your project, with the body already encoded and the markup ready to paste — open [a project](https://missblue.dev/projects) and go to Numbers.
[Next Receiving messages What arrives when they tap send, and how to be told about it.](https://missblue.dev/docs/receiving-messages)