Guide to Onsite Opt-in

Who gets this? Shops on all Postscript plans have access to this feature. Learn more about Postscript Plans.

Onsite Opt-in is an innovative acquisition functionality that keeps shoppers on your website during and after the popup opt-in flow on both mobile and desktop. With Onsite Opt-in, you can:

  • Increase SMS opt-in rates on pop ups to increase list growth compliantly.
  • Keep shoppers on site to maximize order conversion and maintain campaign attribution.
  • Increase conversions and make more money with SMS by significantly increasing your subscriber list.

Onsite Opt-in Overview

Onsite Opt-in utilizes iOS and Android’s one-time password (OTP) autofill technology to secure a compliant and explicit opt-in from site visitors. Check out the full end-user experience of Onsite Opt-in below:


Onsite OptIn Gif.gif



Set Up Onsite Opt-in


  1. From your Postscript dashboard, select Acquisition on the left-side navigation panel.
  2. Select an existing popup or select the Create button in the upper-right corner and choose a desktop or mobile popup. 
  3. Within the Form card, Onsite Opt-in will display as the default opt-in method.
  4. Continue editing your popup as normal (tip: for help on designing your popups, see this guide for mobile and this guide for desktop).
  5. When your popup is designed to your liking, be sure to select Save in the upper-right corner.

Onsite Opt-in Reminder

Onsite Opt-in automatically sends a follow-up text message to any pending subscriber who submitted their phone number to a popup, but did not confirm their opt-in with the one time passcode. Below, we show the user experience and outline key information about Onsite Opt-in Reminder.

OOI Reminder Example.png

  • This functionality is available for subscribers based in the United States only.
  • No additional configuration required for activation.
  • The reminder text is sent 4 hours after the opt-in was initiated.
  • To ensure compliant messaging, your brand's Terms and Privacy Policy will be linked in the reminder message.
  • Onsite Opt-in Reminder works exclusively with Postscript popups using Onsite Opt-in as their opt in method.
  • At this time, neither the reminder text nor the 4-hour delay can be customized.

Key Information

  • Postscript coupons texted to subscribers after opting in with Onsite Opt-in will automatically apply at checkout when you include a Postscript-generated discount code and your shop link in your popup welcome message.
  • Fondue CashBack will also automatically apply at checkout when you include your shop URL (with the Fondue code appended) in your popup welcome message.
  • At this time, Shopify coupons will not auto-apply at checkout when subscribers opt in via Onsite Opt-in.
  • Onsite Opt-in is the default opt-in method for Postscript popups.

Get Support

Have questions? Please feel free to reach out to our wonderful Support team at or via live chat. You can also submit a support request here!

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