Choose the Right Opt-In Method to Build a Clean, Compliant SMS List
Table of Contents
Overview
When setting up SMS marketing, one of the first choices you’ll make is how customers subscribe to your list: single opt-in or double opt-in. Both methods are compliant with TCPA and CTIA regulations, but they come with different risk levels. This guide explains the differences — and why we recommend double opt-in for most Recart merchants.
What Is Single Opt-In?
With single opt-in, customers are added to your SMS list immediately after they enter their phone number (e.g. via popup, checkout, or embedded form). No further confirmation is required.
Risks of Single Opt-In
Pros
- Fastest signup experience
- No additional user actions needed
Risks
- Anyone can enter any number — including one they don’t own
- You may end up sending SMS to people who never gave consent
- Can lead to compliance issues or legal risk, even if you’ve followed technical guidelines
What Is Double Opt-In?
Double opt-in adds a verification step to confirm that the person entering the phone number actually owns it. There are a few methods:
- Two-Factor Authentication (2FA) – Recommended
- A one-time passcode (OTP) is sent to the number
- Customers verify directly on-site, without leaving the page
- Cleanest and lowest-friction double opt-in option
- Confirmation Text Message
- Customer must reply “YES” or “CONFIRM” via SMS
- Requires leaving the website to complete subscription
- Deep Link (SMS App Redirect)
- Customer is redirected to their Messages app to send a reply
- Often causes drop-offs due to distractions
Why We Recommend 2FA
Using a 2FA-based double opt-in ensures that:
- Your list contains only real, consented phone numbers
- You protect your brand from litigation or spam complaints
- You maintain high conversion rates (typically only 2–8% drop-off)
This method strikes the best balance between compliance, list quality, and user experience.
How to Choose Your Opt-In Type in Recart
To select your SMS opt-in type in Recart:
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Go to your Recart dashboard
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Click Opt-in Tools
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Select Create New → Pop-up
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At the top of the popup builder, choose your SMS opt-in type from the available options:
- Double Opt-in (2FA)
- One-Click Opt-in
- Replying “YES” as Consent
Once selected, click Continue to Editing to finish building your popup.
FAQs
Q: Is single opt-in illegal?
A: No — single opt-in is compliant with both TCPA and CTIA guidelines when implemented properly. However, it increases your exposure to risk and abuse.
Q: Will I lose conversions with double opt-in?
A: With 2FA-based verification, most merchants only see a 2–8% drop-off. For most, that’s a small price to pay for legal protection and higher list quality.
Related Resources
This article is based on insights shared in our blog post on SMS subscription best practices.
If you have any questions, reach out to support@recart.com - we're happy to help!