Best Klaviyo Agencies in the UK (2026): 11 Checked Against Klaviyo’s Own Directory

The best Klaviyo agencies in the UK for 2026 start with the three UK firms holding Klaviyo’s top Elite Master badge: PAASE in Bedfordshire, Get Better in North Devon and Underground Ecom in London. Behind them come four Platinum Master agencies (Email Kong, Magnet Monster, VALIX and Melusine Studio) and three at Gold: Evernue Media, Goldsend and Climb & Conquer. Each badge was read from Klaviyo’s partner directory on 29 October 2026; every other detail comes from the agency’s own site.

Retention Control publishes this list and puts itself first. It runs Klaviyo for UK and Irish brands alongside its US clients, but it has no listing in Klaviyo’s directory, and its entry is plain about that. If you are comparing Klaviyo agencies in every country rather than the UK alone, our Klaviyo agencies guide covers the wider field, and our retention agency comparison ranks agencies across email, SMS and loyalty.

Klaviyo’s directory listed 674 partners on 29 October 2026 but offers no filter by country, only by the regions each partner says it serves. So we built the UK count ourselves from the listings and the agencies’ own sites, and found at least 46 UK-based partners at Silver or above: 3 at Elite, 21 at Platinum, 12 at Gold and 10 at Silver, counting both the Master and Advisor tracks and a few overseas firms with a UK office.

• Eleven agencies: Retention Control plus ten with a UK base, from London to Barnstaple, Cheshire and Teesside.
• Badges come from Klaviyo, not from the agencies’ websites. One site claims a tier its listing does not show, and one counts UK Elite agencies differently from us; both are flagged.
• Prices: four publish a monthly figure, in pounds or dollars, and one prices only its audits.
• Disclosure: we run Retention Control. Its team is in Klaviyo’s partner programme, but it holds no directory badge.

UK Klaviyo agencies compared

What changes when your customers are in the UK

UK email marketing runs under different rules from the US. The Privacy and Electronic Communications Regulations (PECR) require consent before you email or text individuals, with one exception, the soft opt-in: you may market similar products to people whose details you collected during a sale, as long as you offered a way to opt out then and in every message since. UK GDPR then governs how the data is stored and how consent is recorded. A UK agency should set up sign-up forms, consent records and suppression around those rules from day one.

Pricing and timing differ too. Prices shown to UK shoppers must include VAT, which matters in every product block a flow pulls in. The UK peak also runs on its own calendar, from Black Friday through the Christmas posting deadlines to the Boxing Day sales, so campaign planning starts earlier than many US calendars. Our UK retention marketing page covers how we handle each of these, and our SMS consent definition explains the texting side.

When a UK-based Klaviyo agency makes sense

• Most of your customers are in the UK or Europe. An agency that works in your time zone and knows PECR and VAT saves rework on every flow.
• You want to meet the team. Several agencies here have offices outside London, which can matter if your business is in the north or the south-west.
• You sell in pounds and euros. Multi-currency stores need product blocks, discounts and flows that respect each market, and UK agencies see that setup every week.

The 11 best Klaviyo agencies in the UK

1. Retention Control: best for brands from $500K a year wanting one fee for flows and campaigns

Retention Control is a retention-only agency for Shopify and DTC brands, serving the UK and Ireland as well as the US and Europe. It plans, writes and runs Klaviyo flows and campaigns along with Omnisend, Brevo and Attentive, and its pricing page lists two retainers in US dollars: $3,500 a month for brands doing $500K to $2M a year, and $5,500 a month above that, adding SMS, testing and loyalty design. A free 60-minute audit comes first, and after a 90-day build the retainer runs month to month.

What to know: the people who run its accounts joined Klaviyo’s partner programme via the sister agency Aqsa Shahzad Official; Retention Control itself holds no directory badge and claims none. It also has no UK office and has not yet published a client result. If an Elite badge or a UK case study matters most, start with the next three entries.

2. PAASE: best for brands moving to Klaviyo from another platform

PAASE is listed at Elite Master and gives its address as Liscombe Park, Leighton Buzzard. Its services include “Configuration and implementation of SMS and email marketing automation flows, from welcome and basket abandonment through to bespoke API driven post-purchase emails.” and it adds “We can also manage all your email marketing campaigns to take the pressure off your team.” (PAASE).

What to know: it sells ongoing retainers but publishes no price, and fully managed campaign sends cost extra on top of a package. Its case studies include “Wattbike Migrating from Campaign Monitor to Klaviyo to achieve 218% revenue increase” (PAASE), and it works across Shopify, WooCommerce, Magento and BigCommerce.

3. Get Better: best for starting with a paid audit before a retainer

Get Better is listed at Elite Master and works from a coworking space in Barnstaple, North Devon. Its homepage says “We’ll handle every aspect of your Klaviyo account, from managing flows and campaigns to overseeing emails and SMS.” (Get Better).

What to know: it publishes prices for its audits rather than its retainers: £199, £400 and £800, with “Prices Exclude VAT – VAT will be added” (Get Better). A case study for Pott Candles reports “Revenue from flow automation grew by 201.30%, increasing from £6,482.61 to £19,532.13.” (Get Better), a useful sign that it takes on smaller brands too.

4. Underground Ecom: best for large brands adding SMS and WhatsApp to email

Underground Ecom is listed at Elite Master and works from Farringdon Road in London. Its London page says “Every brand we work with gets a fully allocated, multi-disciplinary team.” and covers “consent capture, sender authentication and opt-out handling under UK GDPR and PECR” (Underground Ecom).

What to know: it is the largest team here, at “120+ Team Members 25 Languages Spoken” (Underground Ecom), and publishes no price. For Seoul Box it reports “Emails Revenue Growth: 287% Percentage of Total Revenue from Email: 41%” (Underground Ecom). Expect it to suit brands with budgets for a full pod rather than a single specialist.

5. Email Kong: best for Shopify subscription brands on Loop

Email Kong is listed at Platinum Master and describes itself on its about page as “Email Kong is a London-based CRM and retention agency for DTC brands” (Email Kong). Its working-with-us page says “We run Klaviyo email, SMS and Loop subscriptions for Shopify DTC brands, on a monthly retainer.” (Email Kong).

What to know: pricing is in dollars: “Retainers start from $5,000 a month and cover flows and campaigns, including a full flow rebuild.” and sets its terms plainly: “We ask for a 3-month minimum. After that, you can leave any time with 4 weeks’ notice.” (Email Kong). It aims at brands doing roughly $3M to $50M a year, and reports that for Kaori “Klaviyo went from 3.3% to 19% of store revenue.” (Email Kong).

6. Magnet Monster: best for flat-fee sending across four channels

Magnet Monster is listed at Platinum Master and its registered office is in Sale, Cheshire. Its pitch is volume at a fixed cost: “Send unlimited emails, SMS, WhatsApp and Direct Mail for one flat fee each month.” (Magnet Monster), and it says “Over 7 years, we’ve helped 300+ eCom brands with retention marketing.” (Magnet Monster).

What to know: it publishes no figure for the flat fee. Its contracts run under English law, with terms set in each statement of work (Magnet Monster). Its homepage cites “Carved 200% increase in email revenue and over a 50% increase in click rate” (Magnet Monster). See the tier note below before you rely on its badge.

7. VALIX: best for AI-led personalisation on Klaviyo

VALIX is listed at Platinum Master, with a registered office in London and a trading address in Milton Keynes. It promises “Fast Turnaround. No Long Contracts.” and states “VALIX is CYBER ESSENTIALS CERTIFIED” (VALIX), which helps if your buyers ask about data security.

What to know: it works only on Klaviyo and publishes no price. Its FAQ lists monthly management covering campaigns, flow optimisation and deliverability, plus help with Shopify integration and Shopify Markets (VALIX). One case study is titled “How Curlsmith Achieved a 29% Revenue Lift with VALIX AI” (VALIX).

8. Melusine Studio: best for premium fashion and beauty brands

Melusine Studio is listed at Platinum Master and has a London WC1 address, with a team that works remotely. It says “Our boutique team of Klaviyo experts manage everything from lifecycle strategy and segmentation to campaign execution and loyalty programmes” (Melusine Studio), and calls itself “Small by design, think of us as an extension of your team” (Melusine Studio).

What to know: it focuses on premium D2C brands on Shopify and Shopify Plus, and publishes no price. Its work page reports “REFY: Structured post-purchase journey drove +187% in revenue” (Melusine Studio), a beauty brand that fits its focus.

9. Evernue Media: best for seven and eight figure brands that want a dedicated pod

Evernue Media is listed at Gold Master and is a UK company whose team now works remotely. It publishes “Partnerships from £2,500 / month” (Evernue Media) and says “Each brand is supported by a dedicated Evernue pod, limited to six accounts.” (Evernue Media).

What to know: a separate 30-day Klaviyo setup project starts at £4,000 for brands that need one (Evernue Media). It offers a refund “If you don’t feel we’re the right fit within your first 14 days” (Evernue Media). For Instant Swim it reports “£545K attributed lifecycle revenue (+243.7%)” (Evernue Media).

10. Goldsend: best for start-ups that want a founder-led specialist

Goldsend is listed at Gold Master and gives its address as City Road, London. It was “Founded by Clara Toombs who has deep experience in Klaviyo and Braze” and offers “Flexible monthly retainers and consultancy to suit your stage and needs” (Goldsend).

What to know: it is a small specialist rather than a large team, and publishes no price. Its homepage lists “ICO registered” (Goldsend) among its credentials, and a client testimonial there sits beside a 463% year-on-year rise in flow revenue, though the figure is not tied to a named brand.

11. Climb & Conquer: best for smaller brands that want no contract

Climb & Conquer is listed at Gold Advisor and is based in Stockton-on-Tees. It publishes tiered prices: “Around £400 a month typically sits in Campaigns, £900 in Klaviyo Essential, £1,500 in Klaviyo Growth+ and £2,400 or more in Bespoke.” and says “We don’t do contracts, so you can leave at any time.” (Climb & Conquer).

What to know: Advisor is the Klaviyo track for partners that mainly refer brands rather than run accounts, while its own site describes full account management, so ask how it works. Its Klaviyo listing also states “packages start from £1,200/month” (Klaviyo), above the £400 on its site. It reports “40% More Email Revenue for Stairparts Direct in 90 Days with Klaviyo Management” (Climb & Conquer), and also sells SEO and paid ads.

Badge claims we could not match

A badge on a website can be older than the one Klaviyo currently shows. On 29 October 2026 we found two gaps. Neither is a judgement on the agency’s work, but both are worth asking about:

• Magnet Monster cites “Master Elite Klaviyo partner status” (Magnet Monster), and the text of its own Klaviyo listing repeats the Elite claim, while the badge on that listing reads Platinum Master.
• Get Better calls itself “a Klaviyo Elite Agency (one of just 2 in the UK)” (Get Better). Its Elite Master badge checks out, but by our count three UK-based agencies held that badge on 29 October: PAASE, Get Better and Underground Ecom.

How this list was built

Klaviyo’s directory has no country filter, so we scanned every listing’s text and the websites of the 597 partners at Silver and above (77 would not load) for a UK base, then checked each candidate by hand. Badges come from Klaviyo’s listing pages; everything else is quoted from the agency’s own site, and best-of lists were only a way to find names.

We kept agencies that offer ongoing Klaviyo management and show ecommerce or Shopify work. We left out agencies that bill only by the hour, a firm registered outside the UK despite a London team, sites we could not load or read, two sites with placeholder text on the pages we would have cited, and one agency whose case studies showed no email results. Badges and prices change, so open each Klaviyo link before you sign.

Five checks before you sign with a UK agency

1. Open the agency’s Klaviyo listing with them. Note the badge and whether the track is Master, which runs accounts, or Advisor.
2. Ask how they handle PECR and the soft opt-in. The answer should cover sign-up forms, consent records and existing customers.
3. Check the currency and VAT on the quote. Some UK agencies price in dollars and some exclude VAT.
4. Ask for a UK client result. Results from US accounts do not always carry over to a UK list and calendar.
5. Confirm what Klaviyo itself will cost. Klaviyo bills you directly, and the price rises as your contact list grows.

Bottom line

Start with the badge on Klaviyo’s own listing, then judge what it cannot tell you: the price and its currency, the contract, whether the team knows PECR and the UK calendar, and results from brands like yours. The three Elite agencies suit brands ready for a full team; the priced Gold agencies suit brands still building.