The guide to bulk SMS marketing for B2C brands

Start with the intent behind each type of SMS message you plan to send. For example:

• Promotional: flash sales, product promotions, and exclusive discounts

• Transactional: order confirmations, shipping updates, and delivery confirmations

• Informational: event reminders, re-stock alerts, or content-based updates like tips and how-tos

It’s not just what you say—it’s when you say it. A bulk SMS content calendar helps you plan campaigns in advance, avoid message fatigue, and align sends with your wider marketing plan.

So, how often should you text your customers? According to Klaviyo’s SMS research with Recharge, here’s how often shoppers want to receive text messages from brands:

• A few times a week: 32%

• Once a week: 27%

• A few times a month: 16%

• Once a day: 13%

When you send your messages matters as much as how often you send them. Here’s when people are most likely to make a purchase after receiving an SMS, according to the same research:

• Evening: 45%

• Afternoon: 25%

• Midday: 13%

• Morning: 9%

• Late night hours: 8%

You’ll also want to create space and content for seasonal campaigns—like Black Friday, back-to-school, and Boxing Day—when shoppers are actively looking to buy. Use our marketing campaign calendar to map key dates out in advance, and see how planning ahead for peak moments pays off. 

While SMS is great for urgency, it shouldn’t be siloed. Each marketing channel plays a different role in moving customers closer to purchase, so integrate your bulk SMS calendar with other channels like push notifications and email (more on this later).

The golden rule of bulk SMS marketing? Make sure your customers say “yes” first.

Wherever your audience is based, SMS compliance needs to be a priority. Regulations like the TCPA in the US; PECR & GDPR in the UK, and GDPR in the EU, require explicit consent before you send a single message. That means no pre-ticked boxes, no implied consent, and always a clear way to opt out of receiving messages—e.g., “Reply STOP to unsubscribe”.

Timing also matters—did you know it’s illegal to send messages during certain hours? In the US, the TCPA restricts messages during “quiet hours” (typically before 8 a.m. and after 9 p.m.), whilst UK SMS compliance regulations, state brands cannot send SMS marketing messages before 9 a.m. and after 8p.m.)
In France SMS Marketing regulations prohibit the sending of SMS for marketing on Sundays, during French public holidays, and between 10 pm and 8 am on other days

Juggling SMS regulations across multiple countries isn’t the headache it sounds like if you’ve got the right tech. Klaviyo helps you comply with automatic SMS quiet hours so you never send a message outside legal windows. Klaviyo’s SMS deliverability hub tracks performance and deliverability across all your campaigns and safeguards your sender reputation—all from one place.

To grow your SMS list, meet your customers where they are—and give them a reason to opt in:

• Website sign-up forms: Use pop-ups, fly-outs, or embedded sign-up forms to capture attention with incentives like discounts or early access.

• In-store collection: Encourage sign-ups during purchase with exclusive SMS-only offers.

• Social media promotions: Use Instagram Stories, TikTok, or Facebook ads to drive opt-ins with compelling calls to action (CTAs).

• Email list conversion: Invite your email audience to opt in for SMS and tell them what makes SMS sign-up special, like early access or exclusive deals.

A big SMS list is useless if it’s full of disengaged subscribers. Keep your SMS list healthy by:

• Regular cleaning and updating: Remove invalid numbers and opt-outs to maintain deliverability. Klaviyo’s SMS deliverability hub automatically flags deliverability issues like unsubscribe rates and message failures.

• Managing inactive subscribers: Identify subscribers who haven’t engaged in a while. Consider how long they’ve been inactive and when they’re most likely to respond.

• Running re-engagement campaigns: With your list of inactive users, use targeted offers or check-in messages to revive interest.  

With bulk SMS, less is more. The trick is getting to the point quickly while still delivering value.

SMS messages have a standard 160-character limit, so create succinct, impactful messages that prioritise essential information and shortened URLs to maximise readability. 

But keep in mind what your customers actually want. According to Klaviyo’s SMS research with Recharge, these are the top SMS messages customers want more of:

• Shipment and delivery confirmations: 51%

• Coupons or promotional codes: 42%

• Order confirmations: 39%

• Birthday deals: 37%

• Promotion and sales announcements: 32%

Always aim to create urgency—phrases like “limited time offer” or “last chance” can prompt quick action. Messages should also include a clear CTA and value proposition: tell your recipients exactly what they’ll gain and what to do next.

Equally important is keeping your brand voice consistent. SMS might be short form, but it’s still an extension of your brand—maintain your usual tone so customers know exactly who they’re hearing from.

Effective SMS copy has a lot to cover in just a few words, but you can save time with Klaviyo’s SMS assistant. It generates copy tailored to your campaigns and automatically flags language that could violate mobile carrier regulations—so you can send impactful messages with confidence.

Including links and media in bulk SMS

Adding links and media to your SMS campaigns can make them more interactive and engaging. Here’s what you need to know about incorporating them into your bulk SMS strategy:

• Multimedia Messaging Service (MMS) vs. SMS: While SMS messages are limited to text only, MMS lets you add images, GIFs, and even dynamic content. Use MMS messages and emojis sparingly, and with intention—these elements can increase costs, without generating significantly better results.

• Images and graphics: On that note, make sure any images you’re using are relevant and valuable. A photo of a product someone left behind in their cart will likely perform better than a generic graphic design banner.

• CTA best practices: Use just one CTA link at the end of the message, and tell recipients where the link takes them. 

Rich Communication Services (RCS) messaging: RCS messaging enhances text with media like swipeable carousels, high-quality images, videos, GIFs, and audio files—a powerful way to make your SMS campaigns more engaging and dynamic.

As your list grows, follow these SMS best practices to keep engagement high and unsubscribe rates low:

• Be timely and relevant. Send personalised messages based on behaviour, preferences, and time zones.

• Keep it short and clear. Use shortened URLs and generative AI to generate concise copy that prompts action.

Add value. Whether it’s a discount, giveaway, or product launch, make every message worth opening.

Personalised SMS messages start with simple touches—like using a recipient’s first name or a birthday message. But don’t stop there.

When you pull in purchase history to recommend relevant products or use browsing behaviour to follow up on items customers viewed but didn’t buy, your SMS campaigns become far more targeted and effective.

Klaviyo Data Platform (KDP), the customer data platform built into Klaviyo B2C CRM, makes it easy to bring this level of personalisation to life. It unifies customer data from all touchpoints and creates rich customer profiles based on real-time behaviour so you can trigger and send personalised text messages to the right recipients at the right time.

Send messages to specific groups within your audience using SMS segmentation. Fashion brand Magnolia Boutique saw a 49% increase in SMS subscribers after switching to Klaviyo from Attentive. With Klaviyo, they segment customers based on loyalty, purchase behaviour, and engagement to send texts that create more personal customer relationships. 

Here are other ways you can segment your audience with Klaviyo:

• Recency, frequency, monetary (RFM) analysis: Segment customers based on how recently and frequently they’ve purchased, and how much they spend, to send smarter messages—whether it’s a thank-you or a win-back deal.

•  Behavioural segmentation: Whether someone browsed a new arrival, clicked on a product, or left items in their cart, use those behaviours to trigger relevant messages that feel less like marketing—and more like good timing.

•  Demographic and geographic targeting: Location and language-based segments ensure relevant, localised messaging, while age, gender, and other attribute-based segments help you tailor messages that resonate with individual customers. 

Klaviyo’s Segments AI helps you create new groups to target with hyper-specific messaging and promotions. With just a few prompts, you can build audience segments based on a variety of criteria, from location to churn risk.

For example, you could ask Segments AI to create a segment of customers who haven’t purchased in the past 90 days, but recently browsed your site—perfect for re-engagement campaigns.

The results speak volumes: by generating new postal code-based segments for location-specific messaging using Segments AI, luxury blanket brand Saranoni saves 10–30 minutes per segment, compared to manually inputting parameters.

Start with the essential bulk SMS flows and triggers:

• Welcome series: Make your first impression last by greeting new SMS subscribers with engaging intros and incentives.

• Abandoned cart recovery: Win customers back with reminders and direct links to complete their purchase.

•  Post-purchase follow-up: Encourage repeat business and loyalty with a thank-you or other follow-up offer.

• Re-engagement and win-back flows: Reconnect with past customers with personalised recommendations, or a friendly reminder or discount.

Once you’ve set up the essential triggers and flows, you can take your SMS automations further. Klaviyo’s two-way automated SMS conversations enable you to collect preferences, answer FAQs, and recommend products instantly, without manual effort. 

By inviting customer replies, you can foster engagement via messages you’ve already sent. For example, following up on a birthday discount with a message asking how the customer wants to redeem it adds a personal, interactive touch.

Your marketing strategy becomes more cohesive and more effective when email and SMS work together. Each channel amplifies the other’s strengths, and coordinated messages ensure campaigns are timely, relevant, and meet customers where they are. 

Take PrettyLitter, for example. The cat health brand saw 44% YoY growth in revenue from flows in their first month with Klaviyo SMS. One part of their strategy: targeting customers on their preferred channels and sending SMS follow-ups to email campaigns.

With Klaviyo, it’s easy to set up smart campaigns and flows that adapt best to how customers engage. For instance, you might:

• Use SMS at the start of a product or sale campaign to get VIP attention right away, then open it up to your email subscribers after a few days.

• Lead with email when you’re expecting high engagement with a sale to take advantage of the lower cost per message, then use SMS at the end of the campaign to drive urgency for last-minute purchases.

• Use SMS first in higher-intent flows, like abandoned cart, and email first in lower-intent flows, like browse abandonment.

Timing is everything when it comes to SMS. Keep your brand top of mind without overwhelming subscribers with: 

• Klaviyo Smart Sending: Control how many messages you can send within a set period.

•  Klaviyo Smart Send Time: Based on your business’s data, pinpoint the optimal time to text customers and maximise open and click rates.

•  Enabled quiet hours: Klaviyo’s default quiet hours prevent messages from being sent 8 p.m.–11 a.m. based on recipients’ country codes.

•  Klaviyo’s predictive analytics also helps you send messages when customers are most likely to buy, tailors offers based on each person’s spending potential, and even predicts when customers are most likely to place their next order for highly personalised recommendations and targeted SMS marketing campaigns.

Measuring the impact of your bulk SMS strategy isn’t a one-and-done task, but a continuous journey. Set a regular performance review cadence (monthly or quarterly) to keep your marketing sharp as your subscriber list grows.

By comparing your results to industry benchmarks, you’ll quickly identify areas that need improvement. From there, take an iterative approach—making small, data-driven adjustments based on customer profiles and real-time behaviour. This ongoing cycle allows you to refine your strategy with each review, ensuring you’re always optimising for better results.