SMS links

The format

SMS links are defined in RFC 5724, an IETF standard from 2010. Its shape is:

sms:<number>?body=<message>

• The number. RFC 5724 says to write it in international form, starting with + and the country code, unless it only works inside one country or network. Hyphens, dots and brackets are allowed for readability but mean nothing.
• The message. body= is the only field the standard defines. The text is percent-encoded UTF-8, so a space is %20 and a comma is %2C.
• Several numbers. The standard allows a comma-separated list of numbers and says apps should show the whole list before sending.

So sms:+447700900123?body=Hi%2C%20I'd%20like%20to%20book opens a text to +44 7700 900123 with "Hi, I'd like to book" typed.

Make an SMS link

Type the number with its country code and, if you like, a message. You get the link, an HTML version and a QR code.

The tool makes links to one number. Group links aren't handled the same way on all phones, so a single number is the safe choice.

SMS links in HTML

In a web page or an HTML email, the link is an ordinary anchor:

<a href="sms:+447700900123?body=Hi%2C%20I'd%20like%20to%20book">Text to book</a>

Copy the HTML version from the tool: it escapes the characters HTML needs, so it pastes into any page builder or template. Show the number as text nearby as well, so people on a computer can copy it.

What Apple and Google document

This is where SMS links get murky, and it's worth knowing before you rely on the message part.

• Apple. Apple's only page on SMS links is an archived URL Scheme Reference, last updated in 2017. It documents sms: followed by a number using digits, +, - and ., and says the link "must not include any message text". Apple hasn't published a newer page on the format.
• Android. Android's developer docs list sms:, smsto:, mms: and mmsto: as schemes that open a messaging app, and describe passing the message to apps as an extra called sms_body. That's for apps; the docs don't describe ?body= in web links.

So neither company documents a message in web links. Treat the message as a nice extra: test the link on an iPhone and an Android phone, and make sure it still works if the message doesn't appear.

On a computer

Most desktop computers have no app for text messages. An SMS link on a laptop may do nothing, or open a phone-link or messaging app if one is set up. If many of your visitors use computers, put the number as text next to the link, or offer email too.

Where SMS links help

• Bookings and quotes. "Text to book" with a message such as "Hi, I'd like to book an appointment" tells you what they want.
• Print. The tool's QR code opens the same text from a poster or a counter card. See our SMS QR code generator for print tips.
• Emails and newsletters. An HTML link lets people reply by text when that suits them better than email.

Write the message the way your customers would, and keep it short so they can add their own details.

SMS links compared with mailto links

SMS links borrow the idea of mailto links. RFC 5724 compares the two directly. The difference is in the fields: mailto has a subject, cc and bcc, while sms has only the body. For both side by side, read our post on mailto and SMS links. To share a web address inside a text instead, see text message with a link.