The 98% open rate statistic for SMS marketing is real. Almost every text message gets opened. But open rates alone are not what determine whether SMS marketing is worth adding to your Shopify stack. What matters is whether those opens turn into purchases, and whether the economics make sense for your specific business.

The honest answer: for the right Shopify store, SMS is one of the highest-ROI channels available. For stores with low margins, low average order values, or without a robust consent process, the costs and compliance obligations outweigh the returns.

This guide covers how to set it up correctly, stay compliant with UK law, and build campaigns that convert.

Why does SMS work for ecommerce when email already exists?

Email is a powerful channel, but it has a reach problem. Average ecommerce email open rates sit at 20-30%. That means 70-80% of the people you send to never see the message.

SMS is fundamentally different in how it reaches people. A text message lands directly on a customer's lock screen. They see it even when they are not checking their inbox. This creates genuine incremental reach rather than just duplication of your email programme.

Key SMS benchmarks for ecommerce:

Metric	Email benchmark	SMS benchmark
Open rate	20-30%	85-98%
Click-through rate	2-5%	8-12%
Revenue per message sent	£0.01-£0.05	£0.08-£0.25
Unsubscribe rate per send	0.1-0.3%	0.5-1.5%

The higher revenue per message and click-through rate comes at a cost: SMS has meaningfully higher unsubscribe rates than email. Customers are more protective of their phone number than their email address. Every irrelevant text accelerates list erosion. This is why frequency discipline is essential with SMS.

What are the UK compliance requirements for SMS marketing under PECR?

This is the section most guides gloss over. For UK merchants, PECR (Privacy and Electronic Communications Regulations) governs SMS marketing and carries real enforcement risk if you get it wrong.

Explicit opt-in consent is mandatory

Under PECR, you must have explicit, affirmative consent to send marketing texts to UK phone numbers. This means:

The subscriber must actively opt in (a pre-ticked box does not count)
The consent must be specific to SMS marketing, not bundled with email consent or buried in terms
You must tell them clearly what they are opting in to receive
Every message must include a clear unsubscribe mechanism (standard practice: "Reply STOP to unsubscribe")

Using a customer's phone number from a previous purchase without a separate SMS opt-in is non-compliant. Even if they are an existing customer, you need a new, specific consent for SMS marketing.

ICO registration

If you send marketing communications to UK contacts, you must register with the Information Commissioner's Office (ICO) under the Data Protection Act. Registration costs £40-£60 per year for most small businesses. This is not optional.

Consent records

Store evidence of every opt-in: when it occurred, what the subscriber saw when they consented, and their phone number. This is your protection if you receive a complaint to the ICO. Most SMS platforms store this automatically, but verify that yours does.

Unsubscribe processing

When a subscriber replies STOP, you must cease sending marketing messages immediately. Your SMS platform handles this technically, but verify it is working before your first send. A complaint for continuing to text after an opt-out request is exactly the scenario regulators act on.

Which Shopify SMS apps should you use?

Klaviyo SMS

If you already use Klaviyo for email, adding SMS is the lowest-friction option. Klaviyo SMS integrates directly with your existing flows, segments, and customer profiles. You add SMS messages to your existing abandoned checkout, welcome, and post-purchase flows alongside email without rebuilding anything.

Pricing is based on message credits. UK SMS messages cost approximately £0.04-£0.06 per message on Klaviyo. Klaviyo's SMS compliance tools include UK PECR-compliant consent capture forms.

Best for: merchants already using Klaviyo who want a unified email and SMS platform.

Postscript

An SMS-first platform built specifically for Shopify. Postscript has a strong reputation for Shopify-native integrations, compliance tooling, and customer support. Pricing starts at around £100/month plus message costs.

Best for: merchants who want a dedicated SMS platform with deep Shopify integration and strong compliance guidance for UK sends.

Attentive

The market leader for ecommerce SMS, with strong UK capability. More powerful than Klaviyo SMS for complex SMS-specific use cases: better A/B testing, a wider range of triggered flow options, and more sophisticated audience targeting. Higher price point, starting around £300/month for smaller lists.

Best for: larger merchants where SMS is a primary channel rather than a secondary addition to email.

SMSBump (by Yotpo)

Part of the Yotpo ecosystem alongside Yotpo Reviews and Yotpo Loyalty. If you use other Yotpo products, the cross-platform integration is a genuine advantage. Competitive pricing for high-volume senders.

Best for: merchants already invested in the Yotpo ecosystem.

For most Shopify merchants starting out, Klaviyo SMS is the pragmatic choice if you are already on Klaviyo. If SMS is going to be a primary channel, Postscript or Attentive justify the additional cost.

When should you use SMS instead of (or alongside) email?

SMS is not a replacement for email. It is a complementary channel for specific moments where immediacy and high open rates justify the cost and the friction of asking someone to use their phone number.

Where SMS outperforms email

Time-sensitive promotions: Flash sales, limited stock alerts, and same-day offers are natural SMS use cases. The immediacy of text means a "24-hour sale" message reaches customers within minutes. Email sitting in an inbox until tomorrow misses the window entirely.

Abandoned checkout recovery: Adding an SMS touchpoint to your abandoned checkout sequence increases recovery rates meaningfully. A text message sent 60 minutes after abandonment, before the first email hits, catches customers who have moved on from their inbox. For merchants already running email-only checkout recovery, adding an SMS touchpoint typically lifts recovery revenue by 15-25%.

Back-in-stock alerts: High-intent customers who sign up for a stock notification want to know the moment an item is available. An SMS reaches them faster than email and before stock runs out again.

Order and shipping updates: Transactional SMS messages (order confirmed, dispatched, out for delivery) are welcomed by customers and do not require marketing consent under PECR. They generate high satisfaction and create positive brand associations at key moments.

Where email is better

Regular newsletters and content-led campaigns
Long-form product stories or editorial content
Campaigns with images, product grids, and complex layouts
Campaigns to your full list (SMS to everyone every week will destroy your subscriber list)

How do you structure SMS flows for Shopify?

Abandoned checkout SMS flow

Timing: send 60 minutes after abandonment, only if the customer has not completed the purchase.

Message structure: short, direct, personal. Reference the product they left behind if your platform allows dynamic product insertion. Include a short URL back to their cart. Include your unsubscribe instruction.

Example structure: "Hi [First Name], you left [Product Name] in your cart. It's still waiting for you. Complete your order here: [short link]. Reply STOP to unsubscribe."

Welcome series SMS

For subscribers who opt in to SMS at checkout or via a pop-up, send a single welcome message confirming their subscription and setting expectations about what they will receive (how often, what type of content). This reduces early unsubscribes.

Win-back SMS

For lapsed customers in your at-risk segment who have not responded to email win-back attempts, an SMS with a significant offer can recover conversions that email alone would not. Use sparingly: this should be a one-time message per lapsed customer, not a repeated campaign.

VIP and exclusive access SMS

Reserve some SMS slots for your best customers. Early access to a new product drop, a members-only promotion, or a limited-time offer exclusive to SMS subscribers. This creates a positive reason for customers to stay subscribed rather than just being messaged when you want something from them.

What ROI should you expect from SMS marketing?

Realistic expectations for a well-run Shopify SMS programme:

Cost per SMS sent (UK): £0.04-£0.08 depending on platform and volume
Revenue per SMS sent (campaign): £0.10-£0.30 on well-targeted sends to engaged segments
ROI on messaging cost: 3-5x return on message costs for targeted campaigns
Abandoned checkout SMS recovery rate: 3-8% recovery rate on top of email recovery

The economics work best for stores with an average order value above £40 and gross margins above 40%. Below these thresholds, the cost per message relative to revenue generated makes the channel harder to justify.

Build your SMS subscriber list slowly and keep it clean. A smaller list of genuinely opted-in, engaged subscribers will outperform a large list padded with reluctant sign-ups.

How do you build an SMS subscriber list compliantly on Shopify?

Every subscriber must actively opt in. Methods that work:

Checkout opt-in: Shopify allows a separate SMS marketing consent checkbox at checkout. Enable it and make the language specific: "Tick to receive marketing text messages about offers and updates. You can unsubscribe at any time."
On-site pop-ups: A combined email and SMS opt-in. Converts at a lower rate than email-only, but subscribers who opt in to both channels are your most engaged contacts.
Post-purchase opt-in: After a completed order, prompt customers to opt in to SMS for exclusive deals. The positive post-purchase moment increases willingness.
Keyword campaigns: Promote a keyword (text OFFERS to a number) on packaging, in-store, or in email campaigns. Works well for brands with offline touchpoints.

Never add existing customers to your SMS list without a fresh, explicit consent for SMS specifically.

Key actions to take now

Assess whether your average order value (above £40) and gross margin (above 40%) support the economics of SMS
Register with the ICO if you have not already done so
Choose your SMS platform (Klaviyo SMS if already on Klaviyo; Postscript for a dedicated SMS option)
Enable PECR-compliant SMS opt-in at Shopify checkout and in your email capture pop-ups
Add one SMS touchpoint to your abandoned checkout flow as a test send before building out a full programme
Set a frequency cap of no more than three to four SMS messages per month to any individual subscriber
After your first three campaign sends, review unsubscribe rates and adjust frequency if they exceed 1.5% per send

Frequently Asked Questions

Do I need separate consent for SMS and email marketing in the UK?

Yes. Under PECR, email marketing consent and SMS marketing consent are separate. A customer who subscribed to your email list has not consented to receive text messages. You need a distinct, explicit opt-in for each channel. Even when collecting both at the same time, each must have its own clearly labelled, unchecked box.

What is the best time to send SMS campaigns for Shopify?

For most ecommerce stores, Tuesday to Thursday between 10am and 7pm generates the best response. Avoid early morning (before 9am), late evening (after 9pm), and sending at weekends unless the content is specifically time-relevant (a Saturday morning flash sale, for example). Most SMS platforms support time-zone-aware sending.

How do SMS unsubscribe rates compare to email, and is this a problem?

SMS unsubscribes typically run 0.5-1.5% per send compared to 0.1-0.3% for email. This is not a failure; it is the nature of the channel. Customers guard their phone number more closely than their email address. The response is to use SMS selectively: only send when the content genuinely justifies using the channel, and never send at high frequency.

Can I use SMS marketing for a B2B Shopify store?

B2B SMS is subject to the same PECR rules when messaging individuals rather than generic business contact numbers. In practice, most B2B Shopify merchants see poor returns from SMS because business buyers have different expectations around phone communication. Email and account-based outreach typically outperform SMS in B2B ecommerce contexts. For consumer-facing Shopify stores, SMS is far more applicable.

SMS Marketing for Shopify: How to Run Compliant, High-Converting Text Campaigns