> For the complete documentation index, see [llms.txt](https://docs.bird.com/applications/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bird.com/applications/channels/channels/supported-channels/sms/concepts/automatic-sender-selection.md).
# Automatic sender selection
When sending an SMS campaign, you can enable automatic sender selection. When you do this, we will automatically select the best number(s) to send your campaign from, based on the regulations of the country you are sending to and the time you are sending your message.
Example on how to enable automatic sender selections in Campaigns
If you want to send your SMS campaign from a single, specific number, you can toggle this option off, and select the number you want to send from from the drop down.
Example of how to manually select a channel when sending an Emergency Campaign
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