A Marketer’s Guide to Collecting SMS Opt-Ins

Marketing

·

Nov 12, 2025

27 Feb 2024

Guide Takeaways

    • SMS opt-ins are essential for legal compliance and long-term marketing success.

    • Single, double, and soft opt-ins each serve different needs depending on your audience and risk tolerance.

    • Strong compliance requires explicit consent, transparency, correct disclosures, and adherence to regional regulations.

    • SMS opt-ins work best when combined with mobile-friendly forms, pop-ups, shortcodes, and multi-channel promotion.

    • Incentives, personalized messaging, and a predictable cadence help reduce SMS list churn.

    • A well-managed opt-in strategy improves ROI, increases CTRs, and strengthens customer loyalty.

Q&A Highlights

  • What is an SMS opt-in?

    An SMS opt-in is explicit consent from a consumer giving your business permission to send text messages, ensuring legal compliance and reducing spam complaints.

  • What’s the difference between single and double opt-in?

    Single opt-in collects a phone number once; double opt-in requires a confirmation reply, resulting in a cleaner, more accurate SMS list.

  • When can I use a soft opt-in?

    Soft opt-ins apply to existing customers who have an established relationship with your brand, but rules vary by country.

  • What information must be included during opt-in?

    Clear brand identification, terms and conditions, privacy policy, data-rate notices, and opt-out instructions.

  • Why is compliance so strict for SMS compared to email?

    SMS is more intrusive and regulated more heavily, with strict rules around consent, messaging hours, and data usage.

  • How can I increase SMS opt-ins?

    Use mobile-friendly forms, pop-ups, shortcodes, incentives, and consistent multi-channel promotion.

  • How do I prevent SMS list churn?

    Use predictable message frequency, personalization, clear value, and SMS-exclusive incentives.

  • Why are time zones and “quiet hours” important?

    Sending messages outside legal permitted hours can result in fines, blocked messages, or carriers throttling your traffic.

Gathering opt-ins from your customers isn’t only a nice gesture. In many cases, it’s the law. Read on for our tips to make sure you’re doing it right.

SMS marketing can be a powerful channel, but many organizations shy away from it. The challenges around collecting opt-ins for SMS messages are usually two-fold.

First is the struggle of collecting consumer phone numbers in the first place. Resource constraints, unfamiliarity with opt-in strategies, or insufficient infrastructures can stand in the way.

The second obstacle: increased regulation of SMS communications. Improved consumer protection laws around the world have instituted more stringent guidelines for SMS marketing—especially when it comes to gaining explicit consent.

But don’t let these challenges keep you away from SMS. With the right approach, you can start reaping the many benefits of a proper opt-in strategy.

  • Improved return on investment (ROI): More opt-ins means fewer spam complaints and unsubscribers. It also means more prospects who say “yes” to your brand. Once they opt into SMS, they’ll soon be opting into your products and services.

  • Optimized open and click-through rates (CTRs): When your audience opts in, that signals a high-intent prospect that wants to actively keep the conversation going via content, offers, and discounts.

  • Fewer customer complaints: The difference between spam and a genuine conversation is a willingness between two parties. Prospects that opt into your messaging don’t view it as spam, they view it as value.

  • Stronger compliance: Opt-ins serve as an explicit, virtual moment in time where your audience gives you consent to correspond with them. This ensures that your brand upholds industry-standard compliance protocols.

  • Streamlined messaging: SMS marketing is a single-path communication channel that gets delivered straight to your prospects’ handheld devices. This gives you a reliable way to skip complex prospect journeys and also measure performance with confidence.  

Don’t let uncertainty hold your business back from enhancing your customer experience through SMS. In this guide, we’ll break down the basics of opt-ins, why they’re important, and what you can do to quickly build your SMS list.

Note although this guide shares best practices, it is not a substitute for legal advice.

Choose your approach to collecting SMS opt-ins

Choose your approach to collecting SMS opt-ins

A typical SMS campaign sees message open rates of 75 percent—higher than most email campaigns. But a high open rate depends on delivery to a target audience that has chosen to receive those messages. To gather this consent, businesses have three distinct processes to choose from.


Opt-In Type

How It Works

Key Benefits

Considerations

Single opt-in

User enters their phone number once

Fastest list growth, simple setup

Higher risk of fake numbers or errors

Double opt-in

User confirms via follow-up SMS (e.g., “YES”)

Validates real numbers, cleaner lists

Adds friction and may reduce total sign-ups

Soft opt-in

Uses existing customer data to send SMS

Useful for customers already engaged

Complex rules, varies by country, limited to existing relationships


"75% average SMS campaign open rate"

1. Single opt-in

A single opt-in is the simplest form of consent and the most common approach. Consent is gathered simply when consumers add their phone numbers to your SMS list. The customer’s decision to initiate this process is interpreted as explicit consent.

Many businesses will be drawn to a single opt-in because it’s the fastest and most efficient way to build an SMS marketing list—especially if this process meets compliance standards for your industry.

2. Double opt-in

The double opt-in takes a single opt-in process and then sends a follow-up SMS text asking the consumer to confirm their consent. This double opt-in message may ask the number’s owner to reply “YES” or “CONFIRM” to verify consent.

The most significant benefit of a double opt-in is that it confirms that the phone number received is real. In some fillable forms, consumers may enter fake phone numbers to avoid SMS communications with your brand, and this can lead to messages being delivered to the wrong number, or the number being inactive. When you request a double opt-in, you end up with a cleaner SMS list. 

3. Soft opt-in

For existing contacts and customers, soft opt-ins can be used to gather SMS messaging consent. A soft opt-in is an option when you have a customer’s contact info based on their existing customer status and have established a relationship of communicating with that individual.

The rules of soft opt-ins are more complex than single and double opt-ins, and regulations can vary by region. While existing customers who have made purchases or conversions in the past are often eligible for a soft opt-in tactic, many countries permit soft opt-ins for consumers who submit their phone numbers as part of a checkout process but end up abandoning their cart. 

In this scenario, you may be able to send an SMS message reminding them of their cart abandonment, and to also add them to an SMS list for future communication.

Text message conversation where a company requests subscription confirmation with the option to reply 'subscribe'.

A typical SMS campaign sees message open rates of 75 percent—higher than most email campaigns. But a high open rate depends on delivery to a target audience that has chosen to receive those messages. To gather this consent, businesses have three distinct processes to choose from.


Opt-In Type

How It Works

Key Benefits

Considerations

Single opt-in

User enters their phone number once

Fastest list growth, simple setup

Higher risk of fake numbers or errors

Double opt-in

User confirms via follow-up SMS (e.g., “YES”)

Validates real numbers, cleaner lists

Adds friction and may reduce total sign-ups

Soft opt-in

Uses existing customer data to send SMS

Useful for customers already engaged

Complex rules, varies by country, limited to existing relationships


"75% average SMS campaign open rate"

1. Single opt-in

A single opt-in is the simplest form of consent and the most common approach. Consent is gathered simply when consumers add their phone numbers to your SMS list. The customer’s decision to initiate this process is interpreted as explicit consent.

Many businesses will be drawn to a single opt-in because it’s the fastest and most efficient way to build an SMS marketing list—especially if this process meets compliance standards for your industry.

2. Double opt-in

The double opt-in takes a single opt-in process and then sends a follow-up SMS text asking the consumer to confirm their consent. This double opt-in message may ask the number’s owner to reply “YES” or “CONFIRM” to verify consent.

The most significant benefit of a double opt-in is that it confirms that the phone number received is real. In some fillable forms, consumers may enter fake phone numbers to avoid SMS communications with your brand, and this can lead to messages being delivered to the wrong number, or the number being inactive. When you request a double opt-in, you end up with a cleaner SMS list. 

3. Soft opt-in

For existing contacts and customers, soft opt-ins can be used to gather SMS messaging consent. A soft opt-in is an option when you have a customer’s contact info based on their existing customer status and have established a relationship of communicating with that individual.

The rules of soft opt-ins are more complex than single and double opt-ins, and regulations can vary by region. While existing customers who have made purchases or conversions in the past are often eligible for a soft opt-in tactic, many countries permit soft opt-ins for consumers who submit their phone numbers as part of a checkout process but end up abandoning their cart. 

In this scenario, you may be able to send an SMS message reminding them of their cart abandonment, and to also add them to an SMS list for future communication.

Text message conversation where a company requests subscription confirmation with the option to reply 'subscribe'.

Ensure compliance with local SMS opt-in rules

Ensure compliance with local SMS opt-in rules

SMS messaging is subject to far more stringent regulations than email and other types of marketing communications. In the United States, the Telephone Consumer Protection Act has instituted sweeping regulations on SMS messaging practices—including new SMS laws adopted in spring 2023.

Similar regulations have been enacted across the globe, with individual countries setting their own SMS compliance requirements. Whether you’re delivering messages to customers in a single country or around the world, your opt-in strategy must be able to consistently meet these expectations.

Here’s what you need to do:

Gather explicit consent

Not every consumer wants to receive SMS messages from your brand—and if you send messages without gathering their consent, you won’t only tarnish your brand’s reputation with that audience—you’ll also draw the ire of local regulators.

The best form of consent is explicit and written. Filled forms, checked boxes and double opt-in confirmations all provide explicit, documented consent that will satisfy most regulations concerning SMS opt-ins. 

However you gather this consent, make sure the form, web page, or SMS message the consumer is responding to explicitly states that they are agreeing to receive text messages from your business. If consumers don’t realize what they’re signing up for, your business could find itself in hot water.

Provide consumers with required information

Transparency is the best policy. When adding consumers to your SMS list, make sure the sign-up process allows them to access whatever information is required by local compliance laws.

In many countries, a link to your company’s terms and conditions, your privacy policy, a notice about applicable text messages and data rates, and opt-out instructions are either required or recommended. Along with this information, you should make sure your brand name is clear so consumers know who will be sending the messages.

Account for time zone differences and local ‘quiet hours’

When SMS campaigns are delivered to a global audience, timing matters. Many countries have rules governing when SMS marketing messages are allowed. 

In the U.S., for example, the TCPA restricts texts or phone calls between 9:00 PM and 8:00 AM. In France, SMS marketing is banned on Sundays. Failure to follow these guidelines can lead to delays in message delivery and/or hefty penalties levied by local regulators.

Allow for legal review of your opt-in process

Compliance can get complicated. It’s worth a little extra time and resource investment to have your opt-in process reviewed by legal experts who can verify that the right compliance checks are put in place.

This is particularly important when sending messages to a global audience. Legal review can flag instances where your SMS opt-in strategy is out of compliance with country-specific regulations, allowing your business to make adjustments that avoid regulatory trouble. 

Two smartphones display a skincare promotion.

SMS messaging is subject to far more stringent regulations than email and other types of marketing communications. In the United States, the Telephone Consumer Protection Act has instituted sweeping regulations on SMS messaging practices—including new SMS laws adopted in spring 2023.

Similar regulations have been enacted across the globe, with individual countries setting their own SMS compliance requirements. Whether you’re delivering messages to customers in a single country or around the world, your opt-in strategy must be able to consistently meet these expectations.

Here’s what you need to do:

Gather explicit consent

Not every consumer wants to receive SMS messages from your brand—and if you send messages without gathering their consent, you won’t only tarnish your brand’s reputation with that audience—you’ll also draw the ire of local regulators.

The best form of consent is explicit and written. Filled forms, checked boxes and double opt-in confirmations all provide explicit, documented consent that will satisfy most regulations concerning SMS opt-ins. 

However you gather this consent, make sure the form, web page, or SMS message the consumer is responding to explicitly states that they are agreeing to receive text messages from your business. If consumers don’t realize what they’re signing up for, your business could find itself in hot water.

Provide consumers with required information

Transparency is the best policy. When adding consumers to your SMS list, make sure the sign-up process allows them to access whatever information is required by local compliance laws.

In many countries, a link to your company’s terms and conditions, your privacy policy, a notice about applicable text messages and data rates, and opt-out instructions are either required or recommended. Along with this information, you should make sure your brand name is clear so consumers know who will be sending the messages.

Account for time zone differences and local ‘quiet hours’

When SMS campaigns are delivered to a global audience, timing matters. Many countries have rules governing when SMS marketing messages are allowed. 

In the U.S., for example, the TCPA restricts texts or phone calls between 9:00 PM and 8:00 AM. In France, SMS marketing is banned on Sundays. Failure to follow these guidelines can lead to delays in message delivery and/or hefty penalties levied by local regulators.

Allow for legal review of your opt-in process

Compliance can get complicated. It’s worth a little extra time and resource investment to have your opt-in process reviewed by legal experts who can verify that the right compliance checks are put in place.

This is particularly important when sending messages to a global audience. Legal review can flag instances where your SMS opt-in strategy is out of compliance with country-specific regulations, allowing your business to make adjustments that avoid regulatory trouble. 

Two smartphones display a skincare promotion.

Effective strategies to motivate SMS opt-ins

Effective strategies to motivate SMS opt-ins

You’ve addressed the thorny challenges of ensuring compliance for your SMS opt-ins. Now it’s time to figure out how to make those opt-ins happy. From building awareness for your SMS list to incentivizing sign-ups, here are some tactics we recommend:  

Emphasize the benefits of opting in

Give your customers a clear “why” when deciding whether to sign up for SMS messages. Are you using SMS to promote exclusive discounts? Delivering personalized messages? Sharing helpful content, such as seasonal shopping guides?

You’ll have an easier time driving opt-ins when consumers know what they’re getting from this communication channel—especially if your branded SMS experience offers something they’re not getting from other communication channels, such as email and social media.

While setting clear expectations, make sure you clarify how often consumers can expect to receive a text from your business. If you promise to send once every month or week, don’t start blasting out messages every day—it’s a surefire way to trigger a wave of opt-outs.

Create mobile-friendly opt-in forms

SMS is a mobile-first experience. If you want to maximize opt-ins, make sure your tools for collecting opt-ins are optimized for mobile.

Fillable forms should be as user-friendly on mobile devices as they are on text. Don’t restrict your focus on mobile responsiveness to the design of the form itself: consider how a more streamlined form, with fewer fillable forms, might achieve a higher completion rate on mobile devices than a form requesting a bunch of additional information.

Add pop-up forms to your website

Pop-up widgets can promote SMS marketing across your website without requiring individual updates to every web page. These pop-ups can also offer an incentive for signing up, such as a discount code that will be texted to the consumer once their number is added to the list.

MessageBird’s studio makes it easy to create an eye-catching pop-up form that can be added to your website. It’s a simple, effective way to improve your website experience while collecting opt-ins for your SMS strategy.

Simplify the opt-in process with shortcodes

Shortcodes gather SMS opt-ins by asking consumers to text a keyword to a five or six-digit code set up for your SMS marketing program. A floral company, for example, might ask consumers to text “FLOWERS” to a shortcode used by the brand’s SMS strategy. 

By sending the code, the consumer is opting in to receive future messages from the company. They’re a quick, convenient option for gathering opt-ins, and they’re particularly useful when a URL referral or fillable form isn’t an option. TV ads and audio ads, for example, can share the shortcode and the message with an audience that can then initiate the SMS opt-in on their own.

One limitation of this tactic is that shortcodes often don’t translate when marketing to a global audience. In many cases, unique shortcodes must be set up for each country where you’re attempting this opt-in strategy. This adds both complexity and cost since your business has to pay for each unique shortcode it creates.

Use memorable text-to-join keywords

The keywords used in a shortcode opt-in strategy can be used to showcase your brand voice and cultivate a more engaging customer experience. Instead of gathering opt-ins by having consumers text “YES,” for example, choose something specific and fun that is easy for your customers to remember.

It’s a small detail, but it can help create consistency across your branded experience. 

Promote SMS opt-ins across other channels

Spread the word on your SMS strategy however you can. Promote it on social media. Share a referral link in your email campaigns. 

Look outside your digital channels by placing QR codes at your cash registers, or even promoting your shortcode in print advertising. The more places you can plaster your SMS sign-up info, the more opt-ins you’ll be able to capture over time.

Promotional message from Elysia Skincare on social media, offering a 15% discount for SMS sign-up, along with icons for Facebook and text messaging.

You’ve addressed the thorny challenges of ensuring compliance for your SMS opt-ins. Now it’s time to figure out how to make those opt-ins happy. From building awareness for your SMS list to incentivizing sign-ups, here are some tactics we recommend:  

Emphasize the benefits of opting in

Give your customers a clear “why” when deciding whether to sign up for SMS messages. Are you using SMS to promote exclusive discounts? Delivering personalized messages? Sharing helpful content, such as seasonal shopping guides?

You’ll have an easier time driving opt-ins when consumers know what they’re getting from this communication channel—especially if your branded SMS experience offers something they’re not getting from other communication channels, such as email and social media.

While setting clear expectations, make sure you clarify how often consumers can expect to receive a text from your business. If you promise to send once every month or week, don’t start blasting out messages every day—it’s a surefire way to trigger a wave of opt-outs.

Create mobile-friendly opt-in forms

SMS is a mobile-first experience. If you want to maximize opt-ins, make sure your tools for collecting opt-ins are optimized for mobile.

Fillable forms should be as user-friendly on mobile devices as they are on text. Don’t restrict your focus on mobile responsiveness to the design of the form itself: consider how a more streamlined form, with fewer fillable forms, might achieve a higher completion rate on mobile devices than a form requesting a bunch of additional information.

Add pop-up forms to your website

Pop-up widgets can promote SMS marketing across your website without requiring individual updates to every web page. These pop-ups can also offer an incentive for signing up, such as a discount code that will be texted to the consumer once their number is added to the list.

MessageBird’s studio makes it easy to create an eye-catching pop-up form that can be added to your website. It’s a simple, effective way to improve your website experience while collecting opt-ins for your SMS strategy.

Simplify the opt-in process with shortcodes

Shortcodes gather SMS opt-ins by asking consumers to text a keyword to a five or six-digit code set up for your SMS marketing program. A floral company, for example, might ask consumers to text “FLOWERS” to a shortcode used by the brand’s SMS strategy. 

By sending the code, the consumer is opting in to receive future messages from the company. They’re a quick, convenient option for gathering opt-ins, and they’re particularly useful when a URL referral or fillable form isn’t an option. TV ads and audio ads, for example, can share the shortcode and the message with an audience that can then initiate the SMS opt-in on their own.

One limitation of this tactic is that shortcodes often don’t translate when marketing to a global audience. In many cases, unique shortcodes must be set up for each country where you’re attempting this opt-in strategy. This adds both complexity and cost since your business has to pay for each unique shortcode it creates.

Use memorable text-to-join keywords

The keywords used in a shortcode opt-in strategy can be used to showcase your brand voice and cultivate a more engaging customer experience. Instead of gathering opt-ins by having consumers text “YES,” for example, choose something specific and fun that is easy for your customers to remember.

It’s a small detail, but it can help create consistency across your branded experience. 

Promote SMS opt-ins across other channels

Spread the word on your SMS strategy however you can. Promote it on social media. Share a referral link in your email campaigns. 

Look outside your digital channels by placing QR codes at your cash registers, or even promoting your shortcode in print advertising. The more places you can plaster your SMS sign-up info, the more opt-ins you’ll be able to capture over time.

Promotional message from Elysia Skincare on social media, offering a 15% discount for SMS sign-up, along with icons for Facebook and text messaging.

Retaining SMS opt-ins: Best practices for reducing list churn

Retaining SMS opt-ins: Best practices for reducing list churn

Opt-ins are driven by the promise of a better customer experience. If your SMS campaigns don’t deliver on that promise, though, you could see your SMS list shrink as customers opt out of receiving messages.

The keys to retaining SMS opt-ins are simple: deliver on your promises, and continue finding ways to enhance the customer experience through SMS. We recommend the following strategies:

Stick to a regular messaging cadence

Don’t suddenly increase the frequency of your messages—it’s an easy way to send SMS subscribers fleeing. If you want to send more frequent messages to your customers, consider creating a new list around a specific theme and asking existing subscribers to opt into those messages as well. 

Alternatively, you can notify subscribers that you plan on increasing the number of messages they receive, and ask them to let you know if they’re not interested in receiving more frequent texts—in which case you can move those subscribers over to a separate list with less frequent messages.

Tailor messages to individual customers and audiences

Use first-party customer data to create tailored messages based on their preferences and interests. Product recommendations, cart reminders, birthday messages, and other personalized content allow SMS marketing to leverage 1-to-1 communication for a more engaging customer experience.

You can also segment your SMS list to tailor messages around shared interests, or to target ads to customers with similar backgrounds and shopping behaviors. MessageBird allows your business to create many different audiences to enhance the quality of your personalized messaging.

Keep your messaging concise

Short and sweet performs well on SMS. Keep your messages direct and to the point. In countries where URLs are allowed, use shortened URLs to further condense your messages.

In addition to the customer experience benefits, shorter messages may also reduce your SMS costs: if your message goes beyond the max SMS length of 160 characters, you’ll have to pay for two messages instead of one.

Deliver value through incentives

Discounts, VIP deals, flash sales, and exclusive content offer tangible value that will help keep some customers opted into your SMS campaigns. 

For best results, use SMS to deliver deals and promotions that aren’t available through other channels—otherwise, you risk creating a redundant SMS experience, which could increase the risk of opt-outs.

Reminder message from Elysia Skincare, alongside a dashboard tracking a customer’s activity.

Opt-ins are driven by the promise of a better customer experience. If your SMS campaigns don’t deliver on that promise, though, you could see your SMS list shrink as customers opt out of receiving messages.

The keys to retaining SMS opt-ins are simple: deliver on your promises, and continue finding ways to enhance the customer experience through SMS. We recommend the following strategies:

Stick to a regular messaging cadence

Don’t suddenly increase the frequency of your messages—it’s an easy way to send SMS subscribers fleeing. If you want to send more frequent messages to your customers, consider creating a new list around a specific theme and asking existing subscribers to opt into those messages as well. 

Alternatively, you can notify subscribers that you plan on increasing the number of messages they receive, and ask them to let you know if they’re not interested in receiving more frequent texts—in which case you can move those subscribers over to a separate list with less frequent messages.

Tailor messages to individual customers and audiences

Use first-party customer data to create tailored messages based on their preferences and interests. Product recommendations, cart reminders, birthday messages, and other personalized content allow SMS marketing to leverage 1-to-1 communication for a more engaging customer experience.

You can also segment your SMS list to tailor messages around shared interests, or to target ads to customers with similar backgrounds and shopping behaviors. MessageBird allows your business to create many different audiences to enhance the quality of your personalized messaging.

Keep your messaging concise

Short and sweet performs well on SMS. Keep your messages direct and to the point. In countries where URLs are allowed, use shortened URLs to further condense your messages.

In addition to the customer experience benefits, shorter messages may also reduce your SMS costs: if your message goes beyond the max SMS length of 160 characters, you’ll have to pay for two messages instead of one.

Deliver value through incentives

Discounts, VIP deals, flash sales, and exclusive content offer tangible value that will help keep some customers opted into your SMS campaigns. 

For best results, use SMS to deliver deals and promotions that aren’t available through other channels—otherwise, you risk creating a redundant SMS experience, which could increase the risk of opt-outs.

Reminder message from Elysia Skincare, alongside a dashboard tracking a customer’s activity.

Opt into a better customer experience

Opt into a better customer experience

There’s no secret sauce to creating a successful SMS opt-in strategy. All it takes is an organized approach, attention to detail, and the right tools to help you manage opt-ins and compliance at scale.

Everything you need, you can get through Bird. From opt-in forms to pop-up widgets to built-in controls for global compliance, MessageBird’s platform can help you design, implement, and manage an SMS opt-in strategy that lifts your customer experience to new heights.

There’s no reason to fear SMS marketing.

We can prove it. 

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A person is standing at a desk while typing on a laptop.

The complete AI-native platform that scales with your business.

Contact sales

Start for free

© 2026 Bird

Contact Support

A person is standing at a desk while typing on a laptop.

The complete AI-native platform that scales with your business.

Contact sales

Start for free

© 2026 Bird

Contact Support