Clay agencies in Spain are a small, specialized group, which shapes this whole list. When I checked Clay's own partner directory, only a handful of certified partners listed a Spanish base.
I ranked three certified Forge Experts first, then the three Spain-based Clay operators I could verify. The last four slots go to Spanish-speaking Clay shops based elsewhere, each labeled with its real location.
I judged every pick on Clay depth, Spanish-market fit and who owns the tables when the contract ends. One pick is a solo GTM engineer rather than a full agency, which suits smaller budgets.
For broader outbound and marketing agencies, see my review of outbound sales agencies in Spain. This guide follows the same format as my Sydney lead generation agencies list.
Clay sits at the heart of every outbound system B2B Boosted builds. What stood out to me is their stated goal of getting fired within three to six months.
Every table, prompt and workflow lives in accounts your company owns, even after you leave. There is no minimum commitment or termination clause, which is rare in this category.
Their scope runs from list building and triggers to Clay enrichment workflows and copywriting. Spanish is one of four working languages, alongside English, Russian and Portuguese. Every single send also gets human approval before it reaches a prospect's inbox.
I appreciate that B2B Boosted publishes its pricing openly on its Forge Experts profile. A 30-day pilot costs £1,999 against £1,749 per month for a three-month sprint.
Vanderbuild are Clay Cup Vice Champions, ranked second globally and first in Europe for GTM engineering. No other agency on this list holds a stronger Clay credential than that one.
Their work covers outbound campaigns and CRM data automation, which is what GTM engineers do at full scale. They clean and enrich your CRM on a loop, then score every new lead.
They launched 250+ campaigns in 2025 and have built 50+ revenue engines across Europe and the US. Every system runs inside your accounts and stays there when the engagement ends.
One honest caveat: the team works in English and Polish, not Spanish. They suit Spanish companies selling into northern Europe more than the home market.
Finland's Strongest Group runs Clay-powered outbound workflows built on real buying signals. Their site claims 1,200+ meetings booked monthly and 250+ clients across 15 countries.
Localized cold calling is the part of their offer that matters most for Spanish buyers. Spanish is one of eight working languages on the team, including Finnish and Swedish.
Email, LinkedIn, phone and retargeting run as one motion rather than separate channels. Their targeting leans on B2B intent data and live buying signals instead of static lists.
Pricing is pay per realized meeting, which moves most of the risk onto them. I would still agree a written definition of a qualified meeting first.
Barcelona's Conversion Architects is a RevOps agency and certified Clay Solutions Partner. Their whole website runs in English, Spanish and Catalan, which is rare for a Clay partner.
They wire Clay into the HubSpot or Salesforce setup you already run. Most of the work is structural, like scoring models, enrichment and lead routing.
Their recent events include a Clay Club Barcelona session, which tells me they are active locally. Tech Barcelona appears among the case studies published on their website.
Listed in Valencia on Clay's partner directory, Outreacher runs cold email and LinkedIn outreach for B2B software and service firms. The team has been running daily outreach campaigns since 2014, by their own account.
Clay sits alongside Instantly, Smartlead and HeyReach in the sending stack they run. Lists get enriched with job openings, funding and traffic signals before anything sends.
They also offer rented LinkedIn sender accounts belonging to real, ID-verified individuals. I would check that against LinkedIn's terms before relying on it.
Based in Córdoba, Iván Salamanca is a GTM engineer who came from performance marketing and ecommerce. He works solo, which means you deal directly with the person doing the build.
His published project is a LinkedIn outbound engine built on Clay and HeyReach. It finds decision-makers, enriches them and runs multichannel sequences through to booked meetings.
The headline result on that case study page is a +35% change in reply rate. I would treat that as one project rather than a benchmark.
Registered in La Rochelle, France, Hack'celeration still runs a full Spanish-language outbound service. It also appears in Spanish-language comparisons of outbound agencies serving the Spanish market.
Lists come from Apollo, Clay and Sales Navigator, then get enriched and verified before sending. Sending runs on dedicated domains with authentication, warmup and inbox rotation.
Replies and booked meetings route straight into HubSpot, Pipedrive or Attio for reporting. One Spanish comparison rates it as a budget option with lighter personalization.
Dutch Clay Solutions Partner GenFlows was founded by Wouter Harink, who works in six languages including Spanish. The team builds and runs outbound, GTM infrastructure, Clay and RevOps.
Published case studies include 78 demos in 14 days for a creative SaaS brand. Another reports 90+ SQLs in four months with a hard-to-reach healthcare buying committee.
In their fully managed model, your team mostly shows up to the calls it books. That setup suits Spanish companies that have no in-house GTM operator to run Clay.
Paris-based Novlini is a GTM and RevOps studio and a certified Clay partner. It was also named the first Attio Expert Partner anywhere in the world.
Clay sits at the center of their data and signal layer, from TAM sourcing to enrichment. The rest of the stack is composed around it instead of bought as one platform.
Their pitch names a common failure: teams buy Clay, build three tables and stop. Spanish appears among the working languages listed on their Clay directory profile. Paris also shares a time zone with Madrid, which keeps calls simple.
Founded by Jorge Macías, The GTM Engineering Company is a fractional RevOps and automation studio. Clay is the core of every engagement, wired into HubSpot or Salesforce.
You choose a work-along track, where they coach your team inside Clay, or a built-for-you model. Both tracks start by clearing duplicates and stale fields out of your CRM.
The team is US-based but lists Spanish as a working language. I would pick them when a Spanish startup needs the Clay build and the training together.
Most agencies on this list build the Clay table itself very well. Sending, warmup and reply handling are where retainers quietly add up.
The Forge stack covers that sending layer without adding another agency retainer. The Salesforge Clay integration pushes enriched rows straight into live sequences.
The Salesforge team shows how GTM engineers automate sales work from a CLI.
All the agencies on this list can run effective Clay outbound on your behalf. But if your goal is to own the process, control the data, and scale without growing headcount, Salesforge gives you the infrastructure to do it. Try the 14-day free trial - no credit card required.
Keep Clay for data. Send from your own stack.
Try Salesforge free14-day trial. No credit card required.
Or if you're still evaluating agency options, take a look at the certified Forge Experts for vetted agency partners.
| Agency | Location | Best For | Key Focus |
|---|---|---|---|
| B2B Boosted ✓ Forge Certified | United Kingdom | Clay Systems You Own | Clay Builds, Handover |
| Vanderbuild ✓ Forge Certified | Poland | Clay Cup-Level GTM Engineering | GTM Engineering, CRM Data |
| Strongest Group ✓ Forge Certified | Finland | Clay Plus Native-Language Calling | Clay Workflows, Calling |
| Conversion Architects | Barcelona, Spain | RevOps Built On Clay | RevOps, CRM Systems |
| Outreacher | Valencia, Spain | International Cold Email | Cold Email, LinkedIn |
| Iván Salamanca | Córdoba, Spain | Clay And HeyReach Workflows | Clay, HeyReach |
| Hack'celeration | La Rochelle, France | Budget Spanish-Language Outbound | Clay, Apollo, lemlist |
| GenFlows | Netherlands | Managed Clay Meeting Engines | Managed Outbound, RevOps |
| Novlini | Paris, France | Clay Paired With Attio | Clay, Attio, RevOps |
| The GTM Engineering Company | United States | Clay Built Inside Your CRM | CRM Enrichment, Coaching |
Spain's dedicated Clay scene is still small compared with the UK or Germany. The honest shortlist mixes certified partners, local operators and a few Spanish-speaking outsiders.
B2B Boosted is my pick if you want a Clay system you keep. Vanderbuild has the deepest Clay credentials, backed by its Clay Cup result. Strongest Group fits best when you want Spanish-language cold calling alongside email.
If agency fees do not fit, build the list in Clay and send from your own stack. Two weeks of warmup and a month of sending will tell you most of what you need.
Your Clay data. Your sending stack.
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