# Opt-outs

## Why this matters

People must be able to stop messages they don't want. For marketing messages in particular, offering a simple opt-out is part of staying compliant, and it protects your sender reputation.

## How opt-outs work

- Your account has a **stop list** of numbers that have opted out.
- **Every send is checked against the stop list.** Messages to numbers on it are blocked and aren't sent. They show with error code 9000 in [status codes](/docs/reference/sms-status-codes/).
- A number joins the stop list when the recipient uses the opt-out link in a message. Where replies are possible, replying **STOP** also adds them.

A Sender ID can't be replied to, so for messages sent from a name the opt-out link is the only way to opt out.

## Add an opt-out link

1. On the **Send New** tab, under **Use Opt Out:**, tick **Add 17 character opt-out link**.

ExcelSend adds ` ^^oo^^` to the end of your message, which becomes a short link when sent. The recipient clicks it to opt out of your messages.

The link counts as 17 characters, which can push a message into an extra part. The size line includes it. You can also type `^^oo^^` yourself to place the link somewhere other than the end.

## Common problems

**My message went into two parts when I added the opt-out link**
The 17 characters took it over the limit. Shorten the message by 17 characters or more.

**A contact who opted out now wants messages again**
The stop list is managed on the platform, not in the add-in. [Contact us](/contact/).

## Related

- [Replies and Sender IDs](/docs/sending/replies-and-sender-ids/)
- [SMS message parts](/docs/reference/sms-message-parts/)
- [Status and error codes](/docs/reference/sms-status-codes/)

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Source: https://excelsend.com/docs/sending/opt-outs/