By Pete Devkota·Last reviewed ·Editorial · no paid placements
The best SMS marketing agencies for ecommerce, on our ranking, are Chronos Agency for repeat-purchase brands on Klaviyo SMS or Postscript, Flowium for US DTC brands on Klaviyo, and Hustler Marketing for mid-market brands on Klaviyo or Yotpo. BMO Media fits brands staying on Attentive, and Duh Retention fits Postscript brands that want a published price.
Most "best SMS marketing agency" lists are written by an agency that ranks itself first, and plenty of the agencies on them treat SMS as a line on the services page. This list is written by an agency too. We're Email Optimize, a Klaviyo partner agency founded in 2017, and we sit at #5. The difference we're aiming for: every agency below has an SMS service described on its own website, every credential was checked against a partner directory, and every entry tells you which brand it actually fits.
The filter is ecommerce SMS. That means compliant opt-in and list growth, automated SMS flows (welcome, abandoned cart, back in stock, post-purchase), campaigns that share a calendar with email, and reporting that sets SMS revenue against the cost of sending. Platform matters too, so every entry says whether the agency works in Klaviyo SMS, Postscript, Attentive or several of them.
Receipts over adjectives. Where an agency publishes an SMS result, a price or a partner status, we quote it and say where it came from. Where we couldn't verify something, we left it out. Last reviewed October 2026.
About the author. Aeronautical engineer turned ecommerce email specialist. Pete founded Email Optimize in 2017 and is behind $250M+ in attributed email and SMS revenue across 800+ brands. Full profile →
Platforms as stated on each agency's own SMS service page, checked September 2026. Prices are only those the agency publishes on its own site (Duh Retention and Stimulate re-checked 10 October 2026); "Quote only" means it doesn't publish one.
Methodology
How we ranked these
Each agency is judged on five things: (1) an SMS service described on its own website, with scope beyond "we also do SMS", (2) the SMS platforms it works in, (3) verifiable credentials, checked in Klaviyo's partner directory at connect.klaviyo.com and in the Postscript and Attentive partner directories where the agency claims a partnership, (4) SMS-specific results or named clients published on its own site, and (5) a best-fit profile we can state in one sentence. We don't take paid placements or affiliate fees from anyone on this list.
Everything was checked in October 2026. Where an agency's own site and a partner directory disagree on tier, we quote the directory. Tiers, prices and team sizes change, so re-check anything that matters to your decision before you sign. We left off agencies whose SMS offer we couldn't confirm on their own site, and full-service growth agencies where SMS is a small add-on.
The list
The 11 best SMS marketing agencies for ecommerce, ranked
Best for repeat-purchase brands that want SMS run on Klaviyo or Postscript
Klaviyo Elite Master Partner (per Klaviyo partner directory) and Postscript Certified Partner (per Postscript partner directory) · Singapore and Sydney
Chronos has the most complete public SMS evidence of any agency we checked. Their SMS service page covers automated SMS flows (welcome, abandoned cart, post-purchase), manual campaigns, list growth and TCPA-compliant consent, and they're one of the few agencies that appear in both Klaviyo's and Postscript's partner directories. They also publish an SMS-specific result: Olivia Jewelry saw 10x SMS revenue in November and December 2024 against the same period in 2023, per their case study. Clients lean consumable and Australian (The Oodie, Truly Beauty, Organifi). Strongest fit for replenishment-driven brands, and for brands that want an agency comfortable in either Klaviyo SMS or Postscript rather than one platform only.
Listed in both Klaviyo's and Postscript's partner directories
Published SMS result: 10x SMS revenue for Olivia Jewelry, Nov/Dec 2024 vs 2023 (per their case study)
SMS flows, campaigns, list growth and TCPA consent on their SMS service page
Singapore and Sydney offices, delivering across APAC and the US
Best for US DTC brands wanting SMS inside a large, retention-only Klaviyo team
Klaviyo Elite Master Partner (per Klaviyo partner directory) · New York, NY (distributed team)
Flowium's SMS service page covers segmentation and strategy, compliant opt-ins, SMS automations, campaign calendars and A/B testing, built in Klaviyo. They report 1,000+ brands served since 2017, and their Klaviyo partner profile lists clients including True Classic, Dr. Squatch, RSVLTS and Last Crumb. We couldn't find SMS-only results on their site (their case studies report flow and repeat-revenue figures), so judge them on process and bench depth. Strongest fit for US DTC brands on Klaviyo that want email and SMS run by one large specialist team.
Dedicated SMS service page: opt-ins, automations, campaign calendars, testing
Elite Master tier in Klaviyo's partner directory
1,000+ brands served since 2017 (per their site)
Works in Klaviyo SMS rather than Postscript or Attentive
Best for mid-market DTC on Klaviyo or Yotpo that wants a senior, capped-load account manager
Klaviyo Elite Master Partner (per Klaviyo partner directory); Yotpo Premier Partner (per their site) · Jackson, WY (per their site)
Hustler's SMS page covers abandoned cart, order confirmation, promotional and launch texts, and automated SMS flows, run in Klaviyo or Yotpo. They publish SMS-specific numbers for Sunwarrior: 344x ROI on average for SMS flows and 54x ROI on the top product-launch campaign, per their SMS page. They also won Yotpo's Best Retention Marketing Agency award in 2024 per their site, and account managers handle a maximum of three stores. Strongest fit for mid-market DTC brands with a small in-house team, especially those on Yotpo SMS, which few agencies on this list specialise in.
Sunwarrior SMS results published on their SMS page (344x ROI on SMS flows)
Works in Klaviyo and Yotpo SMS; Yotpo Premier Partner (per their site)
Account managers capped at three stores (per their site)
Best for Australian brands running SMS on Klaviyo or Postscript
Klaviyo Elite Master Partner (per Klaviyo partner directory) · South Brisbane, Australia
Andzen's SMS service page covers SMS campaigns alongside email, SMS steps inside automated flows, mobile number capture and loyalty, with the team listed as Postscript Certified and Klaviyo Elite Master certified. Their SMS page quotes one result from an LPD Black Friday project: an SMS data capture strategy that converted at 67.1% against a 1.5% benchmark. Clients include Lovisa, KSUBI and MAAP. Strongest fit for Australian brands at scale that want a local, heavily credentialed agency and need someone who understands the Spam Act and Australian sender ID rules as well as US-style SMS playbooks.
SMS campaigns, SMS in flows and mobile capture on their SMS page
Published result: 67.1% conversion on an SMS data capture strategy for LPD (per their SMS page)
Best for brands that want SMS and email run as one Klaviyo program by a senior operator
Klaviyo Partner · Adelaide, Australia
That's us. We build on Klaviyo and Omnisend, and SMS runs inside whichever of the two carries your email: sender registration, compliant consent, SMS steps inside the flows you already run, campaigns in the same calendar as email, and reporting that sets SMS revenue against the cost of sending. Founded in 2017 by Pete Devkota, with $250M+ in attributed email and SMS revenue across 800+ brands. The SMS-relevant receipts: Pete spent 22+ months as embedded Head of Retention Marketing (Email & SMS) at Relaxium (INC 5000), where email and SMS added +$3M in incremental annual revenue, and Popl took email and SMS from under 20% to 50-60% of revenue over 21 months. Where we're not the pick: if you want an agency to run Attentive or Postscript for you, or SMS is your dominant channel and you want an SMS specialist, others on this list fit better.
SMS inside your email platform: one profile, one flow builder, one attribution model
$250M+ attributed email and SMS revenue across 800+ ecommerce brands
Relaxium (INC 5000): +$3M incremental annual revenue from email and SMS
Attentive and Postscript to Klaviyo SMS migrations with consent records intact
Adelaide HQ with delivery in Australian and North American business hours
Best for UK brands at scale that want SMS and WhatsApp under one CRM roadmap
Klaviyo Elite Master Partner, Klaviyo Agency Partner of the Year EMEA 2025 (per Klaviyo partner directory) · London, UK
Underground Ecom sells SMS and WhatsApp programs alongside email, built in Klaviyo, and describes its SMS work as strategy and lifecycle planning, opt-in capture, flow builds and broadcasts, with GDPR and PECR compliance. That last part matters: UK consent rules are stricter than the US, and a UK-based team is used to them. Clients include AG1, Osprey, Huda Beauty and Chilly's. We couldn't find SMS-only results on their site. Strongest fit for UK and international brands where retention is already a board-level budget line; for a smaller brand, the machine may be bigger than you need.
SMS and WhatsApp programs alongside email (per their site)
UK GDPR and PECR consent handled as standard
Elite Master tier and EMEA Agency Partner of the Year 2025 (per Klaviyo directory)
Sticky Digital positions itself as a Shopify retention agency and runs SMS on Klaviyo, Attentive and Postscript, covering cart recovery, post-purchase and win-back texts, list growth, segmentation and testing. That platform range is useful if you're committed to Attentive or Postscript and want an agency that won't push you to switch. The client list skews beauty and wellness: r.e.m. beauty, NEST New York, Deborah Lippmann, MUD\WTR and PrettyLitter. Their public SMS results are blended with email, so ask for SMS-only numbers in the pitch.
Works in Klaviyo SMS, Attentive and Postscript
Platinum Master tier in Klaviyo's partner directory
Clients: r.e.m. beauty, NEST New York, MUD\WTR, PrettyLitter
Best for brands running Attentive that want an agency fluent in it
Attentive Premier partner (per Attentive partner directory)
BMO Media has a dedicated SMS page covering flow builds (cart recovery, welcome, back in stock, post-purchase and VIP), compliant list growth, campaign planning and email and SMS orchestration, across Attentive, Postscript, Klaviyo SMS and Sendlane. Their Darc Sport case study, run on Attentive, reports the SMS list growing to 41,000 subscribers within two months and a 29.8% increase in SMS revenue. Strongest fit for brands already on Attentive (or Sendlane) that want specialist hands on the platform rather than a Klaviyo-first agency.
SMS flows, list growth and campaigns on a dedicated SMS page
Works in Attentive, Postscript, Klaviyo SMS and Sendlane
Darc Sport (on Attentive): SMS list to 41,000 in two months, +29.8% SMS revenue (per their case study)
Duh Retention is one of the few agencies that publishes its prices: per their site, one-time projects from $2,500, retainers between $5,000 and $12,000 a month, and a minimum of $200,000 a month in Shopify revenue. Retainers include unlimited SMS alongside email and push, plus direct mail, loyalty and subscription work. They're listed at Platinum in Postscript's partner directory. Named case studies include Youtooz, Theory11 and Buffy. Strongest fit for Shopify brands doing $200K+ a month that want SMS volume and a clear price before the first call.
Published pricing: projects from $2,500, retainers $5,000-$12,000/month (per their site)
Minimum $200,000/month in Shopify revenue (per their site)
Best for DTC brands that want a published starting price and a Klaviyo SMS build
Klaviyo Gold Master Partner (per Klaviyo partner directory) · St. Petersburg, FL (per their site)
Stimulate runs two SMS service pages (general SMS marketing, and Klaviyo SMS specifically) covering setup, copy, segmentation, automation, MMS, list growth and TCPA compliance, and says it supports Klaviyo, Postscript and Attentive. Their homepage says "Investment starts at $4k / month" (as of October 2026). Their published results are blended email and SMS: Nursing Queen's email and SMS share of revenue rose from 30.3% to 59.5% in 90 days, per their case studies page. Their site describes them as a Klaviyo Platinum partner; Klaviyo's directory showed Gold Master when we checked.
Published pricing from $4,000/month (per their homepage, October 2026)
Dedicated Klaviyo SMS service page
Supports Klaviyo, Postscript and Attentive (per their site)
Nursing Queen: email and SMS share of revenue 30.3% to 59.5% in 90 days (per their site)
Best for brand-led DTC that wants SMS on a flat monthly fee
Klaviyo Platinum Master Partner (per Klaviyo partner directory; their site shows a Master Elite badge) · Greater Manchester, UK (also registered in Singapore)
Magnet Monster's SMS page covers strategy, promotional and engagement campaigns, personalised messaging built on customer research, and tracking revenue per message and unsubscribes. The commercial model is the distinctive part: per their site, one flat monthly fee covers unlimited email, SMS, WhatsApp and direct mail, so there's no incentive to pad the calendar. Named clients include Waterdrop, Outerknown and Laura Geller. We couldn't find SMS-only results on their site. Strongest fit for brand-led DTC that wants predictable cost and an SMS program that doesn't lean on constant discounts.
Flat monthly fee covering email, SMS, WhatsApp and direct mail (per their site)
Tracks revenue per message and unsubscribes as core SMS metrics
Clients: Waterdrop, Outerknown, Laura Geller
UK and Singapore entities
Practical decision
Which SMS marketing agency fits which brand
Start with your SMS platform and your market, then your size. That narrows the list faster than any ranking.
Replenishment or consumables brand, on Klaviyo SMS or Postscript
→ Chronos Agency. Listed in both partner directories, with published SMS results.
US DTC on Klaviyo wanting a large retention-only team
→ Flowium.
Mid-market DTC on Yotpo SMS or Klaviyo with a small in-house team
→ Hustler Marketing.
Australian brand at scale
→ Andzen, or Email Optimize if you also sell into North America.
Brand that wants SMS and email run as one Klaviyo program
→ Email Optimize. SMS inside Klaviyo (or Omnisend), with Attentive and Postscript migrations.
UK brand, or international brand wanting SMS plus WhatsApp
→ Underground Ecom.
Brand staying on Attentive
→ BMO Media or Sticky Digital.
Shopify brand on Postscript doing $200K+ a month
→ Duh Retention, or Chronos Agency.
Brand that wants a published price before the first call
→ Duh Retention (retainers $5K-$12K/month) or Stimulate (from $4,000/month).
Brand-led DTC wanting flat, predictable cost
→ Magnet Monster.
How to choose
How to choose an SMS marketing agency
SMS is the channel where a bad agency costs you twice: once in fees, and again in a burned list and compliance risk. Ask every agency on your shortlist these questions, and expect specific answers.
Show me SMS-only results. Most agencies report email and SMS blended. Ask for SMS revenue per recipient, unsubscribe rate per send, and SMS revenue against the cost of sending for a client like you.
Which platform, and will you make me switch? Some agencies are Klaviyo-only, some specialise in Attentive or Postscript, some work across all of them. Know which you're buying before you sign.
How do you collect consent? You should hear specifics: opt-in disclosure wording, double opt-in, how checkout consent syncs, and how consent records are stored. Vague answers here are a red flag.
What's your sending cadence? A good agency has a campaign ceiling and a reason for it. "We send daily" is how lists get burned.
How do you handle registration? Toll-free verification, short code applications and, in Australia, the SMS Sender ID Register all take time. The agency should plan around them, especially before Black Friday.
Who writes the texts, and who checks them? 160 characters leaves no room for a careless claim, especially in supplements and health.
Published figures as of October 2026: Duh Retention lists projects from $2,500 and retainers between $5,000 and $12,000 a month. Stimulate lists pricing from $4,000 a month. Magnet Monster charges one flat monthly fee covering email, SMS and other channels. Our own pricing page puts ecommerce retainers at roughly $3,000 to $12,000 USD a month and one-off projects (audits, SMS setups, migrations, flow builds) at roughly $3,000 to $15,000 USD.
The agency fee is only half the bill. You also pay your SMS platform for messages sent, and SMS costs per message in a way email doesn't. Whoever runs your program should report SMS revenue against both the fee and the sending cost. A program that clicks well but costs more to send than it earns is not working.
Do you want a Klaviyo SMS agency or an SMS-platform specialist?
If your email already runs in Klaviyo, a Klaviyo SMS marketing agency keeps both channels on one profile, one flow builder and one attribution model. For most ecommerce brands that's the simpler, cheaper stack, and it's the one we run.
If SMS is your dominant retention channel, or you're committed to Attentive or Postscript for their SMS-specific depth, hire an agency that genuinely works in that platform (Chronos, BMO Media, Sticky Digital and Duh Retention on this list do). Our Klaviyo vs Postscript and Klaviyo vs Attentive comparisons set out where each platform wins.
USA: most agencies here do the bulk of their SMS work in the US, where the rules are the TCPA, carrier requirements under CTIA guidelines, and state laws with their own quiet hours. Ask how they handle consent records and opt-out keywords.
UK: SMS marketing falls under PECR, with a stricter consent bar than the US and a narrow soft opt-in for existing customers. Underground Ecom (London) and Magnet Monster (Greater Manchester) are UK-based.
Australia: the Spam Act 2003 applies, and since 1 July 2026 texts sent from a business-name sender ID that isn't on the ACMA's SMS Sender ID Register show up as "Unverified". Andzen (South Brisbane), Chronos (Sydney) and Email Optimize (Adelaide) are Australian-based.
An ecommerce SMS marketing agency sets up your sending number and registration, collects compliant consent, builds automated SMS flows (welcome, abandoned cart, back in stock, post-purchase), plans and sends SMS campaigns alongside email, and reports SMS revenue against the cost of sending. The good ones protect the list as hard as they grow it, because a burned SMS list is expensive to rebuild.
On our ranking: Chronos Agency, Flowium, Hustler Marketing, Andzen, Email Optimize, Underground Ecom, Sticky Digital, BMO Media, Duh Retention, Stimulate and Magnet Monster. The right one depends on your SMS platform (Klaviyo SMS, Postscript, Attentive or Yotpo), your market (US, UK or Australia) and your size. The "Which SMS marketing agency fits which brand" section maps each profile to a pick.
Published figures as of October 2026: Duh Retention projects from $2,500 and retainers of $5,000 to $12,000 a month; Stimulate from $4,000 a month; Email Optimize retainers roughly $3,000 to $12,000 USD a month and projects roughly $3,000 to $15,000 USD. Magnet Monster charges a flat monthly fee. Your SMS platform's per-message costs are billed separately, on top of the agency fee.
A Klaviyo SMS marketing agency runs text message marketing inside Klaviyo, so SMS shares one customer profile, flow builder and attribution model with your email. It handles sender setup and verification, consent collection through Klaviyo forms and checkout, SMS steps in flows, and campaigns. Chronos, Flowium, Hustler Marketing, Andzen, Underground Ecom and Email Optimize all run Klaviyo SMS.
In-house works if someone on your team owns the calendar, knows the consent rules and can build flows in your platform. An agency makes sense when SMS is new to you, when you are migrating platforms, or when the person running email has no time for a second channel. Either way, set a campaign ceiling and measure SMS revenue against sending cost.
Because leaving ourselves off would hide a relevant option, and ranking ourselves #1 would make the list useless. We put ourselves at #5, said where we fit (brands that want SMS and email run as one Klaviyo program) and where we don't (brands staying on Attentive or Postscript, or SMS-first programs wanting a specialist). We take no paid placements or affiliate fees from any agency listed.