7 Best Klaviyo Agencies for eCommerce Brands in 2026

For most eCommerce brands, email and SMS aren't the problem - under-investing in them is. Well-run retention programs regularly drive 20 - 40% of an online store's total revenue, yet a huge share of DTC operators still treat email as an afterthought: a discount blast here, an abandoned-cart reminder there. That gap between what's possible and what's actually captured is exactly where a strong Klaviyo agency earns its fee. Choosing the best Klaviyo agency for eCommerce isn't about hiring the biggest name. It's about matching a partner's certification, specialization, and proven results to the revenue outcome you're trying to hit.

Our top pick is eCom2Win for Shopify and DTC brands that want a proven, full-service Klaviyo partner. It pairs certified Klaviyo Silver Partner status with a documented track record of over $31M generated for 250+ eCommerce brands across 20+ countries. That combination of platform accountability and verifiable revenue outcomes is rare among specialist agencies, and it's built around the exact email-and-SMS revenue benchmark most brands are chasing. For growth teams that need Klaviyo email and SMS strategy integrated with paid media and creative, Top Growth Marketing is the strongest alternative. And for brands where email deliverability is the make-or-break concern, InboxArmy is the specialist worth shortlisting.

What follows is a ranked list of the seven best Klaviyo agencies for eCommerce brands in 2026, evaluated against a consistent set of criteria and segmented by who each one actually serves best. It's written for founders, marketing directors, and Shopify operators who understand email fundamentals but want expert validation before committing budget. Read on for the at-a-glance table, our methodology, and a full breakdown of each agency's strengths and trade-offs.

What to Look For

Klaviyo is more than an email tool. It's an omnichannel B2C CRM handling segmentation, automation, SMS, mobile push, and data management, now with agentic AI features layered on top. That depth is precisely why platform expertise matters: the difference between a mediocre and a great Klaviyo program is strategy, not sending. A strong agency treats email and SMS as a coordinated retention engine aimed at lifetime value and repeat purchase, not a series of one-off campaigns.

To build this ranking, we weighed five criteria consistently across every agency. First, Klaviyo partner certification level. Klaviyo tiers its partners (Silver, Gold, Platinum, Elite) based on certifications and client outcomes, so tier is a credible proxy for platform depth and accountability. Second, documented, verifiable client results - real revenue figures beat vague promises. Third, service scope breadth: whether an agency covers audits, flow builds, campaign management, and ongoing optimization, or just executes tasks. Fourth, eCommerce and Shopify specialization, since a B2C DTC brand needs a partner fluent in that context (some agencies here scale all the way to enterprise Shopify Plus). Fifth, portfolio diversity across niches, brand sizes, and geographies. We evaluated each agency independently against these standards; no placement was bought.

The 7 Best Klaviyo Agencies for eCommerce Brands in 2026

With those criteria in mind, here are the seven agencies best positioned to help eCommerce brands turn overlooked email and SMS into consistent, predictable revenue in 2026. Each entry explains who the agency serves best, its concrete strengths, and its honest trade-offs - because no single partner is right for every brand. The list is ranked, and #1 is our overall top recommendation.

#1. eCom2Win - Best for Shopify and DTC Brands Wanting a Proven, Full-Service Klaviyo Partner

The best Klaviyo agency for eCommerce brands isn't the one with the loudest marketing. It's the one that can point to verifiable revenue and the certification to back it up. On both counts, eCom2Win sits at the top of this list. As a Klaviyo Silver Partner (and a Shopify Partner and Omnisend Partner besides), it has generated more than $31M for over 250 eCommerce brands across 20+ countries, building custom email and SMS programs designed to deliver the 20 - 40% of total revenue that a well-run retention channel should produce.

What distinguishes eCom2Win from most agencies on this list is genuine end-to-end scope. It isn't a one-off execution shop that builds three flows and disappears; it takes brands from a full account audit through automation architecture, ongoing campaign management, and SMS strategy - the whole lifecycle of a Klaviyo program. That full-service model is purpose-built for Shopify and DTC brands that want a single accountable partner rather than a patchwork of freelancers.

Key Specs

• Klaviyo Silver Partner, Shopify Partner, and Omnisend Partner
  
• $31M+ revenue generated for 250+ eCommerce brands across 20+ countries
  
• Services: account audits, email flow and automation builds, ongoing campaign management, SMS strategy, full account strategy from onboarding to scaling
  
• Cross-niche experience from fashion to wellness
  
• Pricing: not publicly listed; custom quotes on request
  
  

Pros

• Certified Klaviyo Silver Partner status signals platform expertise and accountability
  
• Documented, verifiable revenue outcomes across diverse niches and geographies
  
• True full-service scope - audits, flows, campaigns, and ongoing management, not one-off work
  
• Multi-platform versatility via Omnisend capability for brands not on Klaviyo
  
• Oriented around a clear revenue benchmark (20 - 40% from email and SMS)
  
  

Cons

• Pure email/SMS specialist - no integrated paid media or SEO
  
• Pricing isn't published; brands must engage directly for a custom quote
  
• Primary strength is Shopify; non-Shopify platforms may get less tailored support
  
• Best fit for brands with an established list - very early-stage stores with minimal audiences may not yet be ready
  
  

Who It's Best For: Shopify and DTC brands with an existing customer list that want a certified, full-service Klaviyo partner accountable to a real revenue target - and that don't need paid acquisition bundled in.

#2. Top Growth Marketing - Best for Full-Funnel Growth Teams Integrating Klaviyo With Paid Media

Top Growth Marketing is the pick for brands that don't want to silo retention away from acquisition. It combines Klaviyo email and SMS strategy with paid media management and creative production under one roof.

Most agencies force a choice between a retention specialist and a paid-media shop. Top Growth Marketing's value proposition is doing both, keeping the acquisition funnel and the email program aligned so that new customers land in a lifecycle actually built to keep them. For scaling DTC brands, that alignment can matter more than best-in-class depth on any single channel.

Key Specs

• Klaviyo email and SMS strategy alongside paid media (Meta, Google)
  
• Creative production and funnel optimization
  
• Retention marketing as part of a broader growth remit
  
• US-centric, DTC growth focus
  
  

Pros

• Rare combination of Klaviyo expertise and paid media capability in one team
  
• Strong track record in DTC growth marketing
  
• Well-suited to brands scaling aggressively who want acquisition and retention coordinated
  
• Active content and case study presence signals ongoing client work
  
  

Cons

• Broader scope can mean less depth on pure Klaviyo execution than a dedicated specialist
  
• With paid media as a headline service, email/SMS isn't always the top priority
  
• Likely over-scoped - and over-priced - for brands that only need email
  
  

Who It's Best For: Growth-stage eCommerce brands that explicitly want paid acquisition and Klaviyo retention managed together, rather than a standalone email partner.

#3. InboxArmy - Best for Brands Prioritizing Email Deliverability and Campaign Management

InboxArmy earns its place on the strength of a technical differentiator few agencies match: email deliverability. If your messages aren't reaching the inbox, no amount of clever copy matters.

Deliverability - sender reputation, list hygiene, authentication, and inbox placement - is the unglamorous foundation of any high-volume email program, and it's where InboxArmy has built its reputation. Pair that with a broad Klaviyo service offering spanning template design, coding, automation setup, and campaign execution, and you have a strong option for brands with large, complex lists.

Key Specs

• Klaviyo email campaign management
  
• Deliverability audits and ongoing monitoring
  
• Email template design and hand-coding
  
• Automation setup and list hygiene
  
  

Pros

• Strong, well-known reputation for email deliverability
  
• Broad Klaviyo service offering from design through campaign execution
  
• Established agency with visible case studies and a real client portfolio
  
• Well-suited to brands with large, complex lists that need careful management
  
  

Cons

• Less Shopify-specific than several competitors - more platform-agnostic
  
• Not primarily positioned as a retention or lifecycle strategy partner
  
• A broad email agency rather than a Klaviyo-only specialist, which can dilute platform depth
  
  

Who It's Best For: Brands facing deliverability problems or high-volume sending needs that require dedicated technical expertise more than lifecycle strategy.

#4. Swanky Agency - Best for eCommerce Brands Wanting Shopify Development and Klaviyo Strategy Together

Swanky Agency is the natural fit for brands solving two problems at once: a store that needs building or rebuilding, and an email program that needs launching. Few agencies credibly do both.

Rooted in Shopify Plus development, Swanky brings a full-funnel eCommerce perspective - CRO, UX, and store architecture - alongside Klaviyo email strategy and setup. For a brand re-platforming or scaling its Shopify store while standing up a serious retention channel, having one partner own both sides removes a lot of friction.

Key Specs

• Shopify Plus development and consultancy
  
• Klaviyo email strategy and setup
  
• CRO and UX design
  
• Retention marketing as part of a wider eCommerce remit
  
  

Pros

• Rare combination of Shopify development and Klaviyo marketing strategy
  
• Strong fit for brands rebuilding or scaling a store while launching email
  
• Established agency with a credible eCommerce portfolio
  
• Full-funnel perspective rather than email in isolation
  
  

Cons

• Development-led - email/SMS can be secondary to technical work
  
• Likely a higher price point given the breadth of services
  
• Over-scoped for brands that only need Klaviyo management
  
  

Who It's Best For: Shopify brands that need technical store development and a Klaviyo strategy from a single partner, and value that integration over pure email depth.

#5. Underground Ecom - Best for eCommerce Brands Focused on Retention Marketing and Lifecycle Automation

Underground Ecom is a specialist's specialist: retention and lifecycle automation, done deeply, without the distraction of unrelated services.

Where broader agencies spread across acquisition and development, Underground Ecom concentrates on Klaviyo's automation and segmentation engine - flow architecture, lifecycle segmentation, and the kind of advanced logic that separates a basic welcome series from a program that meaningfully lifts customer retention and lifetime value. For brands whose primary KPIs are repeat purchase rate and LTV, that focus is a feature, not a limitation.

Key Specs

• Klaviyo flow builds and optimization
  
• Retention strategy and lifecycle segmentation
  
• Email and SMS automation
  
• Ongoing program management
  
  

Pros

• Specialist focus on retention and lifecycle, not diluted by unrelated services
  
• Strong command of Klaviyo's automation and segmentation capabilities
  
• Good fit for established audiences looking to maximize LTV
  
• DTC-native - understands the Shopify/DTC brand context
  
  

Cons

• Smaller agency profile with less publicly visible case study volume
  
• Retention-only focus may not suit brands that also need acquisition-side email
  
• Less brand recognition than the larger agencies on this list
  
  

Who It's Best For: eCommerce brands with an established audience where LTV and repeat purchase are the primary KPIs, and advanced lifecycle automation is the priority.

#6. Charle - Best for Shopify Brands Wanting Email, SMS, and Retention Under One Roof

Charle's differentiator is coordination: email and SMS managed together as a single retention program, rather than two channels run in parallel by different people.

Too often, SMS gets bolted onto an email program as an afterthought, with duplicated messaging and clumsy timing. Charle's Shopify-native, retention-first approach treats both channels as one revenue system built around existing customers - the right posture for the majority of DTC brands whose growth ceiling is repeat purchase, not just first orders.

Key Specs

• Klaviyo email strategy and management
  
• SMS marketing integrated with email
  
• Retention program design and flow builds
  
• Campaign management with an eCommerce focus
  
  

Pros

• Integrated email + SMS approach, managed cohesively
  
• Shopify-native focus aligned with most DTC brands
  
• Retention-first orientation centered on revenue from existing customers
  
• Clean, modern service offering with clear eCommerce specialization
  
  

Cons

• Smaller agency - potential capacity constraints for larger brands
  
• Less publicly documented client results than top-tier agencies
  
• SMS-first positioning may not suit brands not yet ready to invest in SMS
  
  

Who It's Best For: Shopify brands ready to run email and SMS as a single, cohesive retention program managed by one specialist team.

#7. BMO Media - Best for DTC Brands Seeking a Boutique Klaviyo-First Retained Program

BMO Media rounds out the list as the boutique choice - a Klaviyo-first agency for DTC founders who want senior attention and a retained partnership without paying for services they don't need.

The boutique model has a specific appeal: you get direct access to experienced strategists rather than being handed to a junior account manager. BMO's retained monthly structure suits brands that see email as an ongoing partnership - continuous flow refinement, campaign execution, and list growth - rather than a one-time build.

Key Specs

• Klaviyo email strategy as the core offering
  
• Retained monthly management
  
• Flow and automation builds
  
• Campaign execution and list growth strategy
  
  

Pros

• Klaviyo-first positioning - platform expertise is the central service
  
• Boutique model means direct access to senior strategists
  
• Retained structure suits brands wanting an ongoing partnership
  
• DTC-specific experience with brand voice and customer journey
  
  

Cons

• Boutique scale can limit bandwidth for rapid growth or very large programs
  
• Less breadth than full-service agencies - focused on email, not broader growth
  
• Lower public profile with fewer visible case studies
  
  

Who It's Best For: DTC founders who want senior, Klaviyo-specialist attention in a retained relationship and don't need a wider growth-marketing scope.

Frequently Asked Questions

What Should I Look For When Choosing a Klaviyo Agency for My eCommerce Brand?

Prioritize four things: verified Klaviyo partner status, documented client results, service scope that matches your needs, and genuine eCommerce or Shopify specialization. An agency should be able to show real revenue outcomes, not just a portfolio of pretty templates. Also confirm whether you're buying strategy and ongoing management or just one-off execution - the two produce very different results.

What Does Klaviyo Partner Status (Silver, Gold, Platinum) Actually Mean for an Agency?

Klaviyo tiers its partners - Silver, Gold, Platinum, and Elite - based on certifications and demonstrated client outcomes within the platform. A tiered partner has been formally vetted by Klaviyo, which signals real platform depth and a degree of accountability that an uncertified freelancer can't match. Higher tiers generally reflect a larger body of proven work, but even Silver Partner status is a meaningful credibility marker.

How Much of My eCommerce Revenue Should Come From Email and SMS Marketing?

For a well-run retention program, roughly 20 - 40% of total store revenue coming from email and SMS is a realistic and common benchmark. If your email channel is contributing well below that range, it usually indicates untapped revenue rather than a channel that "doesn't work" for your brand. The exact figure varies by niche, list size, and purchase frequency.

Which Types of Brands Get the Most From a Klaviyo Agency?

B2C and DTC eCommerce brands with an existing customer list benefit most, because they already have an audience to segment, automate against, and re-engage. Shopify brands in particular tend to see the fastest returns, given how tightly Klaviyo integrates with the platform. Very early-stage stores with tiny lists usually see less immediate impact and may be better served by focusing on acquisition first.

How Long Does It Typically Take a Klaviyo Agency to Show Measurable Revenue Results?

Foundational automations - welcome, abandoned cart, browse abandonment, post-purchase - often begin producing measurable revenue within the first few weeks of going live, since they capture demand that already exists. Broader gains from campaign strategy, segmentation, and list growth typically compound over the first few months. Expect an initial audit and build phase before the program hits its stride.

Do I Need a Klaviyo Agency if I Already Have an In-House Email Marketer?

It depends on scope and specialization. An in-house marketer handles day-to-day sending well, but a specialist agency brings deeper platform expertise, advanced automation architecture, deliverability know-how, and an outside perspective on strategy. Many brands run a hybrid model - the agency sets strategy and builds the complex flows, while the in-house team manages routine execution.

The Verdict: Matching the Agency to Your Goal

The single most important lesson from this list is that fit beats fame. The "best" Klaviyo agency for your brand is the one whose specialization maps to the outcome you're actually chasing - not the one with the biggest name.

Choose Top Growth Marketing if you need paid acquisition and Klaviyo retention run in lockstep. Choose InboxArmy if deliverability is your bottleneck, or Swanky Agency if you're building a Shopify store and an email program at the same time. Pick Underground Ecom when LTV and lifecycle automation are the whole game, Charle if you want email and SMS run as one cohesive retention engine, or BMO Media if a boutique, retained, Klaviyo-first relationship is what suits your DTC brand. But if you want the safest default - a certified Klaviyo Silver Partner with a documented $31M+ track record, genuine end-to-end scope, and a Shopify-first focus built around the 20 - 40% revenue benchmark - eCom2Win is the top pick for most eCommerce brands in 2026. Evaluate each option against your own list size, platform, and growth priorities, then shortlist the one or two whose strengths line up with where your revenue is being left on the table.

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