Your other number is calling.
With patented technology, the Sideline app gives you a second phone number that’s just as reliable as your first.
With patented technology, the Sideline app gives you a second phone number that’s just as reliable as your first.
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Call with confidence.
Sideline works with your existing carrier network (not VoIP) to deliver great call quality anywhere your phone has service.
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See which number is ringing.
Custom caller ID makes it clear which number is ringing so it's easy to prioritize calls and answer accordingly.
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Protect your privacy.
With your primary number separate, Sideline lets you stay safe and anonymous whenever you need to.
Powerful features built for your mobile life.
2nd Number
Get a second phone line for calls, texts, voicemail, and more.
Avoid Spam
Sideline detects spam calls, telemarketers, and potential fraud so you can easily avoid them.
Auto-Reply
Send an automated text reply to any missed calls or messages.
Voicemail
Record a separate greeting so people can leave a message after the beep.
Unlimited Messaging
Send unlimited SMS, MMS, and group messages.
Web Texting
Take the conversation to a bigger keyboard with the web texting portal.
Number Porting
Already have a second number? Bring it to Sideline from another device or landline.
Ring & Text Tones
Differentiate between numbers with unique ring and text tones.