Table of Contents
- Comparison: Single Opt-in vs Double Opt-in
- Best Practices
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
Comparison: Single vs. Double Opt-In
| Factor | Single Opt-In | Double Opt-In (2FA) |
|---|---|---|
| Signup speed | Instant | +5–10 seconds |
| Conversion drop-off | None | 2–8% typical |
| List quality | Lower—may include invalid numbers | Higher—verified numbers only |
| Compliance risk | Higher | Lower |
| Spam complaints | More likely | Less likely |
| Recommended for | Low-risk scenarios | Most merchants |
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:
-
Go to your Recart dashboard
-
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.
Best Practices
- Recommended: Use 2FA double opt-in for all popups to ensure list quality and compliance.
- Recommended: If you use single opt-in, monitor spam complaints and unsubscribe rates closely.
- Recommended: Clearly disclose what subscribers will receive before they opt in.
- Avoid: Using single opt-in for high-volume campaigns where invalid numbers could impact deliverability.
What's Next
Once you've selected your opt-in type, you can:
- Build your popup and customize the design
- Review SMS compliance best practices to stay protected
- Learn more about SMS opt-in types for detailed setup guides
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!