The 5-Step SMS Deliverability Checklist for DTC Brands Running Klaviyo

If you're running DTC on Shopify and Klaviyo, SMS is either your highest-converting channel or your biggest missed opportunity. Most of the brands I audit have the list. They have the flows. But their texts land in spam folders, get blocked by carriers, or worse—never arrive at all.

Run this checklist before every campaign.

TL;DR

• SMS consistently outperforms other channels on open rates—but only when deliverability is prioritized
• Klaviyo's Settings > SMS compliance layer is the first gate you must pass before sending a single text
• Carrier verification and DNS authentication determine whether your sender ID gets flagged or trusted
• A dirty contact list is the fastest way to tank your SMS sender reputation and burn a short code
• Monitoring delivery rates in real time is the only way to catch problems before your campaign dies

1. Lock In Your Klaviyo SMS Compliance Settings Before Sending a Single Text

Before you send one text, open your Klaviyo dashboard and navigate to Settings > SMS. Select every country where you have customers—this determines which TCPA and international compliance rules apply. Sending to an unselected country creates legal and deliverability risk. Next, add your business name, contact info, and opt-in keywords in the SMS settings panel. Draft your HELP/STOP response message now, not after your flows go live. SMS has become a non-negotiable channel for Shopify brands—first-party data and customer access depend on getting these settings right. These settings are the legal gate everything else depends on. Skip this step and your SMS marketing strategy is built on sand.

2. Verify Your Sender ID and Short Code Through Your Carrier

Before launching your first campaign in Klaviyo, initiate verification for your dedicated phone number or short code through your carrier. A verified sender ID signals legitimacy to mobile carriers and cuts your risk of being flagged as spam—critical when you're relying on SMS to reach customers. Review timelines vary by carrier and request volume, so factor that into your launch schedule. Never use a shared or virtual number for high-volume campaigns: sender reputation is tied to the number, not your Klaviyo account. Once you're verified, protect that number—spam complaints from a verified short code can tank deliverability across your entire account.

3. Scrub Your SMS Contact List With a Double Opt-In and Preference Center

Import every SMS contact into Klaviyo and immediately suppress anyone who hasn't explicitly opted in through a keyword, checkout checkbox, or form. Klaviyo unifies customer data across email, SMS, and mobile push, but that unified profile is worthless if it's built on unverified contacts. Set up a double opt-in: customer texts a keyword → receives a confirmation message → confirms → gets added to your active list. Build a preference center so subscribers can manage frequency and topics—lower complaints mean better deliverability. A smaller, fully consented list will consistently outperform a bloated list with high complaint rates. When done right, SMS for DTC brands can achieve dramatically higher open rates than email—but only if your contacts actually want to hear from you. Source ↗

4. Configure DNS Authentication Records for Your SMS Domain

Your branded sending domain needs DNS authentication before Klaviyo can send SMS on your behalf. This works like email SPF/DKIM—it proves to carriers your messages come from an authorized source, not a spoofed number. In Klaviyo, associate your domain under SMS settings, then work with your developer to publish the TXT and CNAME records Klaviyo specifies. Major carriers actively evaluate sender reputation, and unverified domains face an uphill battle for inbox placement. Without proper authentication, your messages get filtered out before they ever reach a phone. Authenticated domains improve routing, reduce filtering, and signal legitimacy to mobile operators screening unverified senders.

5. Monitor Delivery Rate, Block Rate, and Reply Rate in Your Klaviyo Dashboard

Set up a weekly review of your Klaviyo dashboard metrics—delivery rate, block/complaint rate, and reply rate. Klaviyo unifies customer data across SMS, email, RCS, WhatsApp, and mobile push, but only if your campaigns actually reach inboxes. Your goal: delivery rate as close to 100% as possible, block rate near zero, and reply rate as a quality signal for what resonates. If your block rate spikes, pause active campaigns immediately and audit recent sends—carrier enforcement moves fast. Use campaign-level reporting to identify which flows generate the highest reply rates, then double down on what works. Deliverability isn't a one-time setup. It's an ongoing operation.

Deliverability is the difference between SMS that pays for itself and SMS that wastes your best leads' phone numbers. These five steps aren't optional—they're the baseline. Get them right once, monitor them always, and your campaigns will actually land where they're supposed to.

If you'd rather skip the trial-and-error, book a free 15-minute strategy call and we'll walk through your Klaviyo SMS setup in real time.

Frequently Asked Questions

What is SMS deliverability and why does it matter for DTC brands on Klaviyo?

SMS deliverability is whether your text messages actually reach your subscriber's phone—not filtered out, not blocked by a carrier, but delivered to the device. For DTC brands running Klaviyo, that unified customer profile is only valuable if your texts actually arrive. SMS consistently achieves higher open rates than email, making deliverability critical for ROI.

How do I set up SMS compliance in Klaviyo?

Go to Settings > SMS in your Klaviyo account. Select every country where you have customers, add your business information, and configure your opt-in keywords and HELP/STOP response messages. This step governs TCPA compliance for U.S. contacts and international regulations for other markets. It is the legal foundation your entire SMS program sits on—do not skip it or rush through it.

What is the difference between a short code and a dedicated phone number for SMS in Klaviyo?

A dedicated short code (typically 5-6 digits) is built for high-volume DTC campaigns and takes time to obtain but carries strong carrier trust. A dedicated phone number through Klaviyo is faster to set up and works well for mid-volume programs. Avoid shared virtual numbers for any serious DTC campaign—your sender reputation is tied to that number, and problems from other senders on a shared number can impact your deliverability.

How does SMS deliverability compare to email deliverability for DTC brands?