Klaviyo agencies earn their fees in the parts of the platform most brands never finish: the flow architecture behind welcome, browse, cart and post-purchase journeys, the segments that decide who gets which message, and the SMS program that has to sit next to email without doubling up on the same customer. A good Klaviyo agency turns that setup into a predictable share of store revenue. A weak one sends more campaigns and calls it strategy.
This list covers email and SMS retention specialists that build Klaviyo programs for ecommerce brands. Every agency below lists Klaviyo work on its own site, and most appear in Klaviyo’s own partner directory, where we checked the tier each one holds. If you are comparing Klaviyo shops with broader email firms, our roundup of top email marketing agencies and services covers the wider field.
Results figures quoted here are the agencies’ own published claims. Treat them as a starting point for questions on a discovery call, not as guarantees.
Klaviyo Agencies At A Glance
Company
Headquarters
Best For
Core Services
Flowium
Staten Island, New York, US
US DTC brands that want a dedicated Klaviyo team
Klaviyo setup and migration, flows, campaigns, SMS, email design
Andzen
Brisbane, Australia
Brands selling across APAC, North America and Europe
Email, SMS, lifecycle automation, loyalty, Klaviyo CDP and analytics
Chronos Agency
Singapore
Shopify DTC brands focused on flow revenue
Flow architecture, campaigns, SMS, audits, migrations, direct mail
Homestead Studio
United States
Shopify brands that want retention and paid growth together
Email and SMS strategy, copy, design, list growth, paid social
Hustler Marketing
Jackson, Wyoming, US
Stores that want a fixed four-person account team
Email and SMS management, automations, templates, UGC ads
EmailClub
London, UK
Seven and eight figure brands, especially in France and Europe
CRM strategy, Klaviyo implementation, email and SMS campaigns
Brands that want Klaviyo plus heavy template production
Flows, campaigns, template coding, migration, SMS, list hygiene
Best Klaviyo Agencies For eCommerce In 2026
Partner tiers below are the ones shown in Klaviyo’s partner directory or on the agency’s own site at the time of writing. Elite Master is the highest tier in Klaviyo’s partner program.
1. Flowium — Elite Master Klaviyo Partner With A Deep US DTC Client Roster
Flowium is a Klaviyo-first email and SMS agency founded and led by CEO Andriy Boychuk, with its registered office in Staten Island, New York. Klaviyo’s partner directory lists it at the Elite Master tier, the highest level in the program, and its services there cover Klaviyo implementation, platform migration, custom integrations and omnichannel messaging across email, SMS, push and WhatsApp.
The client list is one of the strongest in the category. Its directory profile and homepage name True Classic, RSVLTS, Dr. Squatch, Last Crumb, Swoon, Sky Zone, Balsam Hill and Maison Kitsune. According to its site, Flowium has worked with more than 1,000 brands since 2017, and its published case studies include a sporting goods brand with a 214.9% increase in repeat customer revenue and a home and garden brand with a 164% lift. The agency was also named to the 2025 Inc. 5000 list.
Flowium works across Shopify, Shopify Plus, BigCommerce, Magento and Salesforce Commerce Cloud, so it is not limited to Shopify stores. It also runs Klaviyo training content, which tells you the team spends real time inside the platform.
Best for: US-based DTC brands doing meaningful volume that want a dedicated Klaviyo email marketing agency with a proven record on flows and repeat purchase revenue.
2. Andzen — Back-To-Back Klaviyo Agency Partner Of The Year With Teams On Four Continents
Andzen is headquartered in South Brisbane, Australia, with teams in the US, Canada, the UK, Germany and Spain. It describes itself as the first Klaviyo Elite Master partner in APAC and the fifth in the world, and Klaviyo’s directory confirms the Elite Master tier. The agency also says it won Klaviyo Agency Partner of the Year in both 2025 and 2026.
The service mix is broad for a retention shop: email, SMS, lifecycle automation, loyalty programs, messenger marketing and Klaviyo data platform work, including CDP implementation and segmentation. Its directory profile lists support in English, German and Spanish.
Named clients include Lovisa, ksubi, General Pants Co., Moana Bikini, The Healthy Mummy, Lectric eBikes, MAAP and Janie and Jack. Andzen publishes case studies with numbers: it says Chef’s Edge unlocked $148K in monthly flow revenue within 60 days of going live, and Rose-Hip Vital grew revenue 25% one month after migrating to Klaviyo.
Best for: brands selling in several regions, particularly Australia and New Zealand, that want a Klaviyo partner able to handle data, loyalty and messaging in one team, in more than one language.
3. Chronos Agency — Elite Master Partner Built Around Shopify Flow Architecture
Chronos Agency is headquartered in Singapore with an office in Sydney, according to its Klaviyo directory profile, which lists it at the Elite Master tier. Its own site calls the badge “the highest Klaviyo agency tier” and says the team has worked with more than 500 DTC brands since 2017.
The work centers on email strategy and lifecycle flow architecture, with campaign planning, copywriting, design, segmentation, deliverability and A/B testing layered on top. Chronos also runs Klaviyo account audits and migrations, adds SMS, and treats direct mail as a lifecycle channel, which is less common among email agencies. Platform expertise covers Shopify, Shopify Plus and WooCommerce.
Named clients include The Oodie, Organifi, TheraICE, Truly Beauty, Cadenshae, Forchics and Calecim. The agency says it has driven more than $400M in attributable revenue for clients. It also says the team is about 80 people serving around 60 brands at a time, a ratio worth asking about if you want to know how much senior attention your account will get.
Best for: Shopify DTC brands, especially in beauty, wellness and home goods, that want a Klaviyo partner focused tightly on flow revenue and account audits.
4. Homestead Studio — Elite Master Partner Pairing Retention With Paid Social
Homestead Studio is listed at the Elite Master tier in Klaviyo’s partner directory, and its retention page describes the agency as a Klaviyo Master Elite partner. The directory profile covers Klaviyo implementation, migration, strategy, the Klaviyo data platform, segmentation and omnichannel messaging, plus growth services such as paid media and social-led subscriber growth.
Its email and SMS work is full service: strategy, copywriting, design, implementation, testing, list growth and reporting for both automations and campaigns. Unlike most agencies on this list, Homestead also runs paid social, paid search and landing pages, so acquisition and retention can be planned by the same team.
The client roster leans toward well-known Shopify brands: HexClad, Girlfriend Collective, Casely, ILIA Beauty, Bobbie, Mad Rabbit and Benchmade appear on its site and directory profile. HexClad’s president is quoted on the site saying Homestead helped the brand more than double its business in 2022.
Best for: Shopify and Shopify Plus brands that want their Klaviyo program and paid acquisition planned together instead of split between two agencies.
5. Hustler Marketing — Elite Master Partner With A Four-Person Team On Every Account
Hustler Marketing is an email and SMS agency based in Jackson, Wyoming, per the address on its site, and it holds the Elite Master tier in Klaviyo’s partner directory. It was one of nine agencies Klaviyo announced as new Elite Master partners in December 2022.
Its structure is the main selling point. Each client gets a dedicated team of four (account manager, designer, copywriter and platform specialist), and the agency says account managers handle no more than three stores. Services cover campaigns, automations, template design, SMS and Klaviyo data platform work, along with UGC ad creative and HubSpot CRM support.
Named clients include BlendJet, TAO Clean, Tailored Athlete, VIM & VIGR and Penn Tools. The agency says it has served more than 450 ecommerce brands, generated $110M for clients in 2025, and keeps 65% of clients for two years or more. It also says Yotpo named it Best Retention Marketing Agency for EMEA.
Best for: Shopify, BigCommerce, Magento and WooCommerce stores that want a fixed, named team and clear limits on how many accounts their manager juggles.
6. EmailClub — Elite Master Partner Working In English, French And Spanish
EmailClub is registered in London as EmailClub Ltd and holds the Elite Master tier in Klaviyo’s partner directory. It positions itself as the agency for seven and eight figure ecommerce sites, and its directory profile says brands with monthly sales above $100k can apply to work with it.
The team is large for a specialist: its site cites more than 90 CRM specialists, and its Klaviyo profile notes work in English, French and Spanish. Services include Klaviyo implementation, platform migration, lifecycle strategy and SMS, across Shopify, Shopify Plus, BigCommerce, Magento and WooCommerce.
Its client base has a strong French accent, with 900.care, Eden Park, Unbottled, Native Union and Laboratoires de Biarritz named on its Klaviyo profile. The agency says it has generated €200 million for clients since 2021 and that CRM activations average a 35% contribution to client revenue.
Best for: established brands with at least $100k in monthly sales, particularly French and European labels that want Klaviyo programs written natively in more than one language.
7. Mailody — Dedicated Klaviyo Agency For The DACH Market
Mailody GmbH is based in Linz, Austria, and calls itself a dedicated Klaviyo agency. It was among the agencies Klaviyo named as new Elite Master partners in December 2022, and its site describes it as the only Klaviyo Elite partner in the DACH region.
Services cover Klaviyo email marketing, migrations, deliverability support, WhatsApp and print mailings. Deliverability gets real attention here, which matters for German-speaking markets where providers such as T-Online filter aggressively: one case study on its site covers clearing spam problems and unblocking T-Online addresses for Junglück.
The client list includes Blackroll, Paul Hewitt, NIKIN, Schleich, Everdrop, Reishunger, Giesswein and Lush. Mailody says it doubled Paul Hewitt’s email revenue after a two-week migration and generated more than €700k in additional revenue for BB Verpackungen. Across clients, it reports €20M in email revenue from more than 100 ecommerce brands.
Best for: ecommerce brands selling in Germany, Austria and Switzerland that need German-language Klaviyo programs and careful deliverability management.
8. ElliotDigital — Platinum Master Klaviyo Partner For UK Shopify Brands
ElliotDigital describes itself as a full-stack DTC retention marketing agency in London. Klaviyo’s partner directory lists it at the Platinum Master tier, with a focus on Europe and on Shopify and Shopify Plus stores.
The scope is tightly email and SMS: strategy, automation, segmentation, design, copywriting and ongoing optimization. That narrow focus suits brands that already have acquisition covered and want a specialist to own the retention channel. The agency also offers free Klaviyo audits as an entry point.
Testimonials on its site come from SURREAL, Magic Mind, Days Brewing, PÄRLA, HUX and XITE, and its directory profile also names Personalised Co and Cornelia James. HUX’s co-founder is quoted saying ElliotDigital helped the brand reach 50% of revenue through Klaviyo, a useful benchmark to raise when you compare proposals.
Best for: UK and European Shopify brands that want a smaller, founder-led Klaviyo partner rather than a large agency with layers of account management.
9. Mastrat — Platinum Master Partner That Only Does Email And SMS
Mastrat, which brands itself as Retention Pros, is a Toronto-based agency listed at the Platinum Master tier in Klaviyo’s partner directory. Its profile is explicit that email and SMS are the only channels it works in, which makes it one of the most focused shops on this list.
Engagements start with what the agency calls “The Real McCoy Audit,” then move into strategy, content calendars, design and copy, project management and deliverability monitoring. Its site lists retention and loyalty programs, personalization and subscriber engagement among its services, and its directory profile points to experience in health and beauty, apparel, travel, and toy and hobby.
Clients named on its site and profile include Trtl, DYLN, Pete’s Real Food, Modernist & Co., CityLocs and Freebird (formerly Freedom Grooming). Freedom Grooming’s co-founder is quoted saying Mastrat accounted for about 28% of revenue over a 180-day period, and Modernist & Co.’s president says email and SMS consistently bring in about 30% of revenue. The agency says it has generated more than $300M for DTC brands.
Best for: growing Shopify DTC brands that want a pure email and SMS specialist and do not need paid media or web development bundled in.
10. InboxArmy — Klaviyo Master Silver Partner With A Large Template Production Team
InboxArmy is an email marketing agency based in Grapevine, Texas. Its Klaviyo page calls it a certified Klaviyo partner agency and displays a Klaviyo Master Silver badge. The agency says it has partnered with more than 5,000 brands since 2016, across many email platforms as well as Klaviyo.
The Klaviyo service list is detailed: strategy, flows, campaign management, template design and coding, migration, segmentation and predictive analytics, SMS, push notifications, list hygiene and audits. Template production is a particular strength, which helps brands that send a high volume of designed campaigns.
Its Klaviyo page publishes several client results: London Store saw a 1,100% increase in email revenue in nine months, Maven Lane earned $700,000 in email revenue in six months, and RCJuice tripled its email marketing revenue. Overall, the agency reports more than $1B in attributed email revenue and $115M in attributed SMS revenue.
Best for: brands that want a Klaviyo email marketing agency with deep production capacity and a long track record, and that are comfortable with a partner below the top Klaviyo tiers.
How To Choose A Klaviyo Agency
What Klaviyo partner tier does the agency hold, and does it matter?
Check the agency’s profile in Klaviyo’s partner directory rather than relying on a badge on its homepage. The agencies on this list range from Master Silver up to Elite Master, the top tier, and a higher tier generally signals an agency that runs many Klaviyo accounts. It does not tell you whether the team assigned to you is senior, so treat tier as a filter and the people on your account as the deciding factor.
Who will actually work on my account?
Ask for names, roles and how many other accounts each person handles. Some agencies publish this: Hustler Marketing caps account managers at three stores. Others will tell you if you ask. A strategist juggling fifteen brands will not have time to rethink your segmentation each quarter.
How will the agency measure revenue from email and SMS?
Klaviyo credits a message with orders placed within a set window after someone engages with it, which can flatter results. Agree up front on the attribution window, on whether you look at Klaviyo-attributed revenue or incremental revenue from holdout tests, and on what share of total store revenue you expect email and SMS to drive. Several agencies on this list publish client examples in the 25% to 50% range, which gives you a sense check against the case studies you are shown.
Does the agency start with an audit of my existing flows?
The best first deliverable is usually an audit of your current flows, segments, sign-up forms and deliverability, not a new campaign calendar. Fixing a broken browse abandonment flow or a welcome series that never splits buyers from non-buyers often pays more than months of extra sends. Ask to see a sample audit before you sign.
How does the agency handle SMS alongside email?
SMS costs money per message and annoys customers faster than email, so it needs its own consent collection, frequency rules and suppression logic. Ask how the agency decides which messages go by text, how it stops the same customer getting an email and an SMS for the same event, and how it handles compliance for opt-ins in each country you sell to.
Does the agency know my platform, market and language?
Most Klaviyo partners are strongest on Shopify. If you run BigCommerce, Magento or Salesforce Commerce Cloud, confirm the agency has live clients there. The same goes for markets: a German or French customer base needs copy written natively, and deliverability rules differ by mailbox provider, which is why regional specialists such as Mailody and EmailClub exist.
Conclusion
The Klaviyo agencies on this list share the same core skill: building flows, segments and campaigns that turn a store’s customer data into repeat revenue. Where they differ is scale, region and scope. Flowium, Andzen, Chronos and Homestead bring top-tier Klaviyo status and large client rosters; EmailClub and Mailody serve specific European markets in their own languages; ElliotDigital and Mastrat keep the work narrow and focused; and InboxArmy offers production depth across platforms.
Start by checking each shortlisted agency in Klaviyo’s partner directory, ask for an audit of your current account, and compare proposals on who does the work and how results will be measured. Retention works best when acquisition is pulling in the right customers, so if you are reviewing paid media at the same time, see our list of top PPC agencies for ecommerce brands.
