7 Best Klaviyo Email Marketing Agencies for DTC and Ecommerce Brands

Quick comparison: seven agencies at a glance

Use this table to scan the essentials (starting price, partner tier, and proof) before you jump on a discovery call. The “Last verified” column shows when we confirmed each fact in Klaviyo’s live directory or another public source.

Agency	Primary strength	Starting price	Named ecommerce clients	Klaviyo tier	Evidence type	SMS scope	Last verified	Confidence
InboxArmy	Embedded execution and deliverability	Quote required	Maven Lane, BoieUSA	Listed (Klaviyo service partner directory)	Four named case studies	Yes	September 2026	High
Flowium	Pure-play lifecycle scale	Custom	True Classic, Dr Squatch	Elite Master	Agency-reported 30 percent portfolio average	Yes	September 2026	High
Chronos Agency	Global, high-volume DTC	Custom	Garvee, The Oodie (logo)	Elite Master	Multiple named case studies	Yes	September 2026	High
Underground Ecom	Enterprise UK/EMEA	Custom	AG1	Elite Master	Award plus logos	Confirm	September 2026	Med-High
Fuel Made	Shopify CRO + email	From $7,500 per month	SAS NOLA, Tuft & Paw	Master Elite	SAS NOLA 40 percent revenue share	Yes	September 2026	High
Magnet Monster	Profit-first retention	Custom	waterdrop, Wild	Platinum Master (directory) / Master Elite (site)	Named wins, no average	WhatsApp + SMS	September 2026	Med-High
The Email Marketers	Eight-figure brand focus	From $4,400 per month	Llama Naturals	Platinum Master	Self-published case wins	Yes	September 2026	Med-High

Confidence reflects depth of publicly available evidence, not agency quality.

How we scored the seven agencies

We built a 100-point rubric so you can audit our picks, not just take them on faith.

Criterion	Weight	What we looked for
Named case studies with baselines	18	Public, client-approved numbers, not screenshots
Lifecycle architecture and testing cadence	14	Flow coverage, A/B cadence, holdouts
Attribution discipline	12	Click-only reporting, Apple-MPP handling, incrementality tests
Current Klaviyo partner tier and certifications	12	Verified in the live directory
Deliverability and data privacy	10	SPF, DKIM, DMARC, Gmail/Yahoo compliance
Integration depth (Recharge, Gorgias, Loop)	10	Working examples, not logo slides
SMS and cross-channel scope	8	Strategy plus consent handling, if offered
Pricing transparency	7	Published floor, term length, exit notice
Independent reviews and client sentiment	6	Recent Clutch/Trustpilot reviews
Thought leadership and education	3	Tutorials, teardown posts, conference talks
Total	100

Evidence labels we apply to every data point

1. Directory-verified (live Klaviyo listing)
2. Named case study (public baseline plus outcome)
3. Agency-reported average (portfolio figure, unaudited)
4. Secondary source (press release, award, talk)
5. Undisclosed (no public proof; scores zero)

Blank fields stay blank; we don’t guess. Each fact carries a “last verified” date so you know when it was checked, because partner tiers, prices, and even headcounts change quickly in the Klaviyo ecosystem.

InboxArmy: best for embedded execution and deliverability

InboxArmy is a Texas-based email and SMS agency that works inside Klaviyo and more than 40 ESPs in total. Migration headaches, broken automations, and inbox issues are its daily work (not paid ads or CRO).

Proof of fit (last verified September 2026)

• Maven Lane: +$700,000 email revenue in six months
• RC Juice: 400 percent lift in monthly revenue from cart-abandonment automation
• BoieUSA: 770 percent holiday-revenue spike; list grew from 2,000 to 100,000

How an engagement works

• Dedicated team: account manager as your single contact, plus strategist, copywriter, designer, developer, and ESP specialist
• Four-week onboarding and kickoff to audit data, warm domains, and agree the revenue KPIs
• Weekly calls and a living roadmap covering flow gaps, test cadence, and inbox reputation

Commercial terms

Quote-based pricing with no hidden fees and no long-term lock-ins. Need only a migration and a handful of flows? They’ll scope exactly that.

Know the limits

InboxArmy is email-first. If you need CRO, paid media, or SEO, pair them with another specialist. The four-week ramp can feel slow if you’re chasing a launch next Friday.

When deliverability is on fire or flows are half-built, this crew fixes the leaks quickly, cleanly, and measurably.

Flowium: best pure-play lifecycle specialist

Flowium is an Elite Master Klaviyo partner that focuses on one thing, email and SMS lifecycle, at scale.

Why they’re on the list (last verified September 2026)

• More than 1,000 ecommerce clients and $352 million in self-reported email revenue
• Portfolio average: 30 percent of store revenue from Klaviyo, click-only attribution
• Named wins: True Classic saw a 46 percent increase in seven days; Last Crumb and Dr Squatch appear on the client roster.

What you get

• End-to-end support: migrations, core flow builds, weekly campaigns, SMS orchestration, quarterly strategy resets
• Deep bench: dedicated strategist, copywriter, designer, technical specialist
• Education hub: teardown videos and tutorials you can review before you buy

Things to check on your discovery call

1. Starting fee and contract term (pricing is bespoke).
2. Strategist client load; ask for the exact number of brands on their calendar.
3. Deliverability ownership: who monitors SPF, DKIM, DMARC and fixes issues?
4. Holdout-testing cadence and how they report incremental lift.

Best fit: growth-stage DTC brands that want a fully staffed retention department without hiring in-house.

Chronos Agency: best for global, high-volume DTC

Chronos Agency is an Elite Master Klaviyo partner headquartered in Singapore with strategists across APAC and North America.

Proof of scale (last verified September 2026)

• More than 500 DTC brands on retainer
• $400 million in cumulative client email revenue (self-reported)
• Garvee: $1.6 million Q4 email revenue; 1,067 percent year-over-year growth after flow rebuild and tighter attribution

What they do differently

• Localised flows by market, language, currency, and tax rules
• Sync with product feeds and help-desk data for market-specific triggers
• Offices in Singapore and Sydney with an 80-plus team, so APAC and North American hours are covered

Important checks before you sign

1. Minimum revenue: Chronos starts around $10 million in annual brand revenue.
2. Custom pricing; confirm monthly minimum and pod workload.
3. Deliverability ownership: ask who manages SPF, DKIM, and DMARC across multiple sender domains.
4. Holdout or incrementality testing cadence and how results are reported.

For eight-figure brands juggling storefronts on three continents, Chronos turns email and SMS into a revenue engine grounded in local nuance, not one-size campaigns.

Underground Ecom: best for enterprise-level UK and EMEA brands

London-based Underground Ecom holds Klaviyo’s Elite Master badge and earned Klaviyo’s Agency Partner of the Year EMEA 2025, announced at K:BOS 2025 in Boston (per the agency’s announcement, verified September 2026).

Why it matters for enterprise teams

Underground Ecom runs retention for names such as AG1, its featured case study, alongside more than 150 global clients. Each engagement begins with a forensic deliverability audit, then layers on region-specific flows, GDPR and PECR-compliant SMS, and inventory-aware merchandising logic.

Operational model

• Account pod: strategist, designer, copywriter, data analyst
• Holdout testing on major flows; Klaviyo revenue reconciled against store data before wins are claimed
• Custom pricing; ask for the monthly minimum in the proposal

Due-diligence checklist

1. Confirm U.S. support hours if your headquarters is stateside.
2. Ask whether full SMS orchestration is included or billed separately.
3. Request two EMEA case studies with baseline, timeframe, and attribution settings.

For high-volume Shopify Plus or Adobe Commerce brands juggling GDPR, VAT, and multilingual catalogs, Underground Ecom supplies the enterprise guardrails and creative depth needed to turn complex data into predictable cross-border revenue.

Fuel Made: best for pairing Shopify CRO with Klaviyo

Fuel Made is a Master Elite Klaviyo partner and long-time Shopify Plus agency that bundles conversion-rate optimisation (CRO) and lifecycle marketing under one retainer.

Why they made the cut (last verified September 2026)

• Retainer starts at $7,500 per month
• SAS NOLA case study: 40 percent of total online revenue now comes from Klaviyo; 135× email ROI and 37× SMS ROI
• Typical client range: $5 million to $100 million in annual revenue (stated in FAQ)

How an engagement works

A joint CRO and email audit first, then rebuilt core flows while onsite tests run, then ongoing sprints that alternate campaigns and CRO experiments (ask for the exact timeline on the call). Revenue per recipient and onsite conversion rate are the lead KPIs.

Questions to ask on your call

• Which deliverability metrics (SPF, DKIM, DMARC, spam rate) does Fuel Made own?
• What attribution window and click-only versus open-plus-click settings drive the 40 percent claim?
• How many active clients does your lead strategist handle?

Best fit: Shopify brands that want one team to drive more add-to-carts onsite and more repeat orders in Klaviyo without mediating between separate CRO and email vendors.

Magnet Monster: best for profit-first, non-discount retention

Manchester-based Magnet Monster helps more than 300 DTC brands grow repeat revenue without training customers to wait for “20 percent off” blasts (last verified September 2026).

Proof points

• Carved: 200 percent lift in email revenue and 50 percent higher click rate after flow rebuild
• French Florist: more than 20 percent revenue growth while the attribution window was cut in half
• Wild: full subscription-flow overhaul that supported the brand’s Unilever acquisition
  (All metrics are self-reported by Magnet Monster; request raw dashboards on your call.)

What makes them different

• Builds flows around zero-party data, loyalty milestones, and post-purchase surveys, not blanket discounts
• Operates email, SMS, WhatsApp, and direct mail from a single roadmap
• Publishes free retention blueprints and teardown videos you can review before signing

Questions to ask

1. Current Klaviyo tier (profile lists Platinum Master in some places, Elite in others; confirm live).
2. Minimum retainer and average strategist workload.
3. Deliverability ownership: who monitors SPF, DKIM, and DMARC?
4. Holdout-testing cadence and how incremental lift is reported.

Best fit: brands that care about contribution margin and storytelling more than perpetual discount codes.

The Email Marketers: best for eight-figure brands needing a wider retention stack

Santa Monica-based The Email Marketers focuses on brands already past the eight-figure mark and publishes its prices up front.

Snapshot (last verified September 2026)

• Klaviyo tier: Platinum Master (live directory)
• Starting retainer: $4,400 per month; average engagement $6,500 per month
• Scope: email, SMS, loyalty, referrals, memberships, subscriptions, and direct-mail triggers
• Named client: Llama Naturals (vitamin gummies); request KPI deck on your discovery call

Why consider them

The agency wires every retention lever (points, perks, referrals, and recurring orders) into a single Klaviyo profile so flows can trigger based on membership status or loyalty tier, not just last purchase.

Questions to verify before signing

1. Latest flow performance stats (revenue per recipient, repeat-purchase lift) for a brand your size.
2. Deliverability ownership: who fixes SPF, DKIM, and DMARC if issues arise?
3. Attribution settings behind any revenue percentages they share.
4. Seniority of the strategist on weekly calls and their current client load.

If your store already nailed the basics of email and now needs a multi-channel retention engine, including loyalty and memberships, The Email Marketers offer pricing clarity and a broad toolset.

Which agency fits which type of ecommerce brand?

Start with your biggest constraint (budget, geography, or skill gap), then use this matrix to build a two-agency shortlist.

Your situation (primary constraint)	First agency to call	Key qualifier to double-check
Migration issues, inbox problems, or fragmented ESP history	InboxArmy	Confirm they own SPF, DKIM, and DMARC fixes
Need a large team to run email and SMS at scale (between $3 million and $20 million revenue)	Flowium	Ask for strategist client load and holdout-test cadence
Multi-storefront brand selling in three or more regions	Chronos Agency	Ensure localisation and time-zone support match your markets
Enterprise UK or EMEA brand with GDPR and PECR complexity	Underground Ecom	Verify the monthly minimum and SMS region coverage
Shopify brand that also needs CRO and theme work	Fuel Made	Pin down how many CRO hours sit inside the retainer
Profit-focused brand that avoids constant discounting	Magnet Monster	Request flow KPIs that exclude incentive codes
Eight-figure brand wanting loyalty, referrals, or memberships	The Email Marketers	Ask for three references with similar average order value and tech stack

If two or more rows feel relevant, shortlist both agencies and give them the same discovery brief. Consistent inputs make comparison easier.

How to choose the right Klaviyo agency

Clarify the work first. Do you need

1. A one-off migration,
2. An always-on email and SMS team, or
3. A full retention department that owns loyalty, referrals, and memberships?

The clearer the scope, the faster you can disqualify the wrong partners.

Match scope to brand stage

• Less than $1 million revenue: focus on core flows, list growth, and deliverability basics.
• $1-$20 million: add A/B testing, revenue-per-recipient targets, SMS, and simple integrations.
• More than $20 million: demand holdout tests, cohort lifetime-value dashboards, and deep data plumbing (Recharge, Gorgias, Loop). Work only with agencies that show named proof inside your band.

Check the team model

Ask who sells the deal and who runs it week to week. A strategist juggling more than eight clients usually means thin mind-share. Confirm that copy, design, development, and deliverability are in-house to avoid bottlenecks.

Inspect flow architecture

Great agencies go beyond welcome and cart to browse, replenishment, subscription-churn, VIP, and sunset flows, each with triggers, filters, and branch logic. Request a real flow map from a similar brand.

Demand testing discipline

Look for a rolling test calendar, sample-size math, and a win/loss log. Key metrics: revenue per recipient, click-through lift, placed-order rate, not inflated Apple-privacy opens.

Audit reporting

Ask for a live dashboard that splits:

• flows versus campaigns
• email versus SMS
• new versus returning-customer revenue
  Confirm click-only versus open-plus-click attribution windows.

Read the contract

Month-to-month or quarterly terms signal confidence; twelve-month lock-ins without performance clauses are red flags. Spell out who owns templates, domains, and data, and require a written hand-over plan.

Work through this checklist and you’ll narrow the field from “Who’s best?” to “Which two agencies both pass? Now let’s negotiate.”

Questions to ask on an agency sales call

Use the same list with every vendor so answers stay comparable.

• What is your current Klaviyo partner tier, and can you open the live directory link right now?
• Which certifications do the strategist, copywriter, designer, developer, and deliverability lead on our account hold?
• Who will be our lead strategist after signing, and how many brands do they manage today?
• Walk me through the first 30 days, week by week.
• Which three flows would you prioritise for our brand, and why?
• How do you treat Apple-MPP opens in segmentation and attribution?
• Do you run holdout or incrementality tests? How often, and what size samples do you use?
• Which attribution window will you recommend, and do you report click-only revenue?
• How do you monitor SPF, DKIM, DMARC, and spam-rate thresholds? Who fixes issues?
• Share a sample client report that splits flows versus campaigns, email versus SMS, and new versus returning-customer revenue.
• Is SMS strategy included in the retainer or billed separately?
• Which of our existing integrations (Recharge, Gorgias, Yotpo, Loop) have you implemented before?
• What are the minimum contract term, setup fee, and notice period to exit?
• Who owns templates, copy, domains, and data if we part ways?
• May we speak with two current clients of similar size and vertical?

Red flags when hiring a Klaviyo agency

Group these warning signs under three headings (metrics, process, and contract) so you can spot trouble in seconds.

1. Metrics and attribution

• Guaranteed open rates or revenue percentages. Apple Mail Privacy Protection auto-fires opens for a large share of Apple Mail users, so “thirty-five percent open rate” promises are meaningless.
• Revenue-share fees with no incrementality tests. If the agency refuses holdouts, you may pay commission on sales that would happen anyway.
• Screenshots with no client name, baseline, or timeframe. Ask for redacted dashboards that show dates and attribution windows.

2. Process and delivery

• “Klaviyo handles deliverability.” Gmail requires aligned SPF, DKIM, and DMARC plus spam rates below 0.3 percent; an agency must own fixes.
• One-size five-flow packages. Every SKU mix and purchase cycle needs different triggers, filters, and branches.
• No discussion of Apple-MPP opens, click-only revenue, or holdout testing. If they can’t explain those in plain English, they’re behind the curve.

3. Contract and ownership

• Twelve-month lock-ins with no performance out clause. Confident partners work month to month or quarterly.
• Agency owns your sending domain or templates. You should keep all creative and infrastructure assets.
• Vague exit language. Require a written hand-over plan covering flows, code, copy, segments, and suppression lists.

Spot just one of these and press for a fix. Find two or more? Keep interviewing.

How much does a Klaviyo agency cost?

Recent pricing round-ups place reputable Klaviyo retainers between roughly $1,500 and $18,000 per month, with most growth-stage brands landing in the $2,500 to $10,000 range (YOCTO’s July 2026 pricing guide, which compiles four published rate cards). Treat the figures below as directional, not a quote.

Engagement scope	Typical monthly fee	Best-fit annual revenue
Audit or one-time flow build	$500-$10,000 total	Pre-scale stores
Entry retainer	$1,500-$3,000	Less than $3 million
Mid-market program	$2,500-$10,000	$3 million to $15 million
Premium email and SMS	$7,500-$15,000	$15 million to $50 million
Enterprise or multi-region	$15,000-$18,000	More than $50 million

Why the spread?

1. Send volume. Doubling active recipients roughly doubles design, testing, and deliverability work.
2. Flow depth. A fourteen-flow program with holdouts costs more than a starter welcome and cart pair.
3. Creative complexity. Custom photography, motion graphics, and dynamic blocks add hours quickly.
4. Data plumbing. Integrating Recharge, Gorgias, or a warehouse beats pasting a discount code.
5. Team seniority. A strategist handling four brands bills higher than one juggling twenty.

Remember the add-ons

Klaviyo software fees, SMS credits, and integration apps (loyalty, reviews, quizzes) sit on top of the agency bill, so budget for them before you sign.

Agency versus freelancer versus in-house: which route pays off?

There’s no universal winner: cost, control, and risk shift as your brand grows.

Option	Typical monthly cost*	Best for	Core advantage	Main risk
DIY / founder-led	$0 (time only)	Less than $1 million revenue	Zero cash outlay	Slow learning, limited rigour
Specialist freelancer	$2,000-$6,000 per project	One-off migration or design sprint	Deep focus, short ramp	Single point of failure
Klaviyo agency	$3,000-$10,000 retainer	$1 million to $50 million revenue	Multidisciplinary pod and process	Higher fee, less day-to-day control
In-house team	$12,000-$25,000 for salaries and tools	More than $20 million steady workload	Full control, brand immersion	Recruiting cost, skill gaps
Hybrid (owner and agency)	$5,000-$15,000	$5 million to $25 million scaling	Balance of strategy and execution	Clear role boundaries required

*Costs are directional ranges compiled from 2026 published rate cards (YOCTO, The Email Marketers, InboxArmy’s pricing guide). They exclude Klaviyo software and SMS fees.

How to decide

1. Map every retention task (strategy, copy, design, development, deliverability, reporting) to a named owner. Empty boxes reveal hiring or vendor gaps.
2. Forecast workload. A single flow rebuild doesn’t justify a full-time hire; thirty monthly campaigns might.
3. Value your time. Founders spending twenty hours a month in Klaviyo are already “paying” an implicit salary at typical executive rates.
4. Stress-test continuity. Ask freelancers and agencies for their backup plan if a key team member is out.
5. Run an audit first. A fixed-fee health check ($500-$5,000) often clarifies whether you need a freelancer’s sprint, an agency retainer, or a staff hire.

Choose the path that covers each task today and can stretch without breaking six months from now.

Conclusion

The seven agencies above all appear in Klaviyo’s partner directory with public proof behind them, but they solve different problems. Start from your biggest constraint: migration or inbox trouble points to InboxArmy, scale to Flowium, multi-region selling to Chronos Agency, UK and EMEA compliance to Underground Ecom, Shopify CRO to Fuel Made, discount-free retention to Magnet Monster, and eight-figure loyalty programs to The Email Marketers. Shortlist two, give both the same discovery brief and sales-call questions, and compare flow maps, testing cadence, and click-only reporting side by side. Budget for Klaviyo and SMS fees on top of the retainer, check the contract for ownership and exit terms, then decide whether an agency, a freelancer, or an in-house hire covers every retention task.

To read more content like this, explore The Brand Hopper

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