SaaS & B2B + London
Best SaaS & B2B AI Agencies in London (November 2026)
17 SaaS & B2B-specialized AI agencies based in London. Top-ranked: Fast Data Science, Elsewhen, N-iX.
16 of the 17 agencies listed have documented SaaS & B2B client work, verified against published case studies.
Shipping an AI feature is easy; shipping one users keep after week two is not. These agencies build copilots, embedded assistants, and AI-native products for software companies—handling evaluation pipelines, latency budgets, and per-request model costs that decide whether the feature survives contact with real usage. The core disciplines are AI Development for production integration and AI Agents for assistant and workflow features, backed by published SaaS work rather than standalone demos.
Market snapshot
Pricing for SaaS & B2B AI agencies in London
Of the 17 SaaS & B2B AI agencies on this page, 14 carry complete hourly rate ranges. Across them, rates span €20–€260, with a median around €65/hr. Across the register, rated agencies in London bill €65–120/hr (20 rated).
“Of the 17 SaaS & B2B AI agencies in London on AIAgencies.eu, 14 carry an hourly rate range, from the agency itself or a third-party directory; the median of those 14 is about €65/hr (November 2026).” https:/
/ www. aiagencies. eu/ industries/ saas/ london# market- snapshot
European AI agency hourly rates by country and region →
| Tier | Hourly rate | Agencies |
|---|---|---|
| Budget | Under €100/hr | 8—N-iX, Marionete, Softblues, Hexploits, Vention, Old St Labs, Pixelette Technologies, Opinov8 |
| Mid-tier | €100–149/hr | 3—Transparity, Found, iCentric Agency |
| Premium | €150–199/hr | 2—NOVOS, Kelriva AI |
| Top tier | €200+/hr | 1—Fast Data Science |
Team capacity in London
All 17 agencies on this page disclose team size. The distribution breaks down as:
- Boutique (<10)4 agencies—Fast Data Science, Nebuli, Hexploits, Kelriva AI
- Small/mid (10-49)5 agencies—Marionete, iCentric Agency, Softblues, NOVOS, ClickSlice
- Mid studio (50-99)3 agencies—Elsewhen, Found, Old St Labs
- Large studio (100+)5 agencies—N-iX, Transparity, Vention, Pixelette Technologies, Opinov8
Ranked agencies
Rankings updated · Newest review
Fast Data Science
#3London, United Kingdom
Client evidence: 8 documented clients overall
Best for: Pharma, research and public-sector buyers with an NLP problem on unstructured documents that has to survive review.
Elsewhen
#19London, United Kingdom
Elsewhen is a London product consultancy working with technology and financial-services companies, pairing product design and engineering with AI and cloud delivery.
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N-iX
#23London, United Kingdom
Client evidence: 4 documented clients overall
Best for: Enterprises with large in-house engineering teams that want AI adoption or ML work measured against an agreed baseline.
Transparity
#40London, United Kingdom
Client evidence: 8 documented clients overall
Best for: UK enterprises, charities and public bodies already on Microsoft 365 and Azure that want Copilot adopted and governed.
Found
#41London, United Kingdom
Client evidence: 8 documented clients overall
Best for: UK consumer brands in retail, insurance and hospitality that want AI applied inside paid search, SEO and campaign data.
Marionete
#42London, United Kingdom
Client evidence: 6 documented clients overall
Best for: Banks and insurers that need the data and MLOps platform under their AI built to regulated-industry standards.
iCentric Agency
#52London, United Kingdom
iCentric Agency is a London and Bedfordshire digital consultancy building custom platforms for enterprise clients, with machine-learning pricing, document processing and agentic tooling among its published specialisms.
Softblues
#68London, United Kingdom
Client evidence: 5 documented clients overall
Best for: Early-stage B2B product teams and smaller UK or Irish firms scoping a first voice agent, agent pipeline or Claude rollout.
Nebuli
#96London, United Kingdom
Client evidence: 5 documented clients overall
Best for: Organizations wanting a private, self-hosted generative AI workspace over their own documents rather than a public LLM.
Hexploits
#101London, United Kingdom
Hexploits is a London software consultancy that builds AI platforms and cloud infrastructure for startups, taking product engineering from architecture through to production hosting.
Vention
#104London, United Kingdom
Client evidence: 10 documented clients overall
Best for: Venture-backed product companies adding engineers to an existing team, with AI as one feature inside the software work.
Old St Labs
#105London, United Kingdom
Client evidence: 29 documented clients overall
Best for: Founders and small UK firms building a first web or mobile product with an LLM feature inside it.
NOVOS
#120London, United Kingdom
Client evidence: 5 documented clients overall
Best for: Consumer e-commerce brands that want to be named in AI answers through SEO and digital PR, with share-of-answer tracking.
Pixelette Technologies
#136London, United Kingdom
Client evidence: 13 documented clients overall
Best for: Founders commissioning a first blockchain or AI product build on a startup budget who will check references before signing.
Opinov8
#137London, United Kingdom
Client evidence: 6 documented clients overall
Best for: Teams adding cloud, data or modernization engineers who want AI coding tools applied to that delivery.
ClickSlice
#139London, United Kingdom
Client evidence: 6 documented clients overall
Best for: UK online retailers that want an existing SEO campaign extended to how ChatGPT, Gemini and Perplexity recommend brands.
Kelriva AI
Verified: the agency confirmed ownership from a company email address, and the listing passed editorial review#144London, United Kingdom
Kelriva AI is a London AI consultancy that builds document processing systems and AI agents for UK businesses, with a focus on regulated sectors such as financial services. We automate the extraction, checking and routing of data from contracts, KYC files, compliance filings and invoices, and build LangGraph agents that take over multi-step approval and review workflows. Every engagement is scoped in writing and delivered at a fixed fee. We work vendor-neutral and build on the systems a business already uses.
Other industries served by London SaaS & B2B agencies
Beyond SaaS & B2B, these 17 agencies also publish experience in:
| Industry | Agencies with stated experience |
|---|---|
| FinTech | 9 of 17 — Elsewhen, N-iX, Transparity, Found, Marionete, Vention, Pixelette Technologies, Opinov8, Kelriva AI |
| E-commerce | 9 of 17 — Found, iCentric Agency, Softblues, Vention, Old St Labs, NOVOS, Pixelette Technologies, Opinov8, ClickSlice |
| Healthcare | 5 of 17 — Fast Data Science, Transparity, Softblues, Nebuli, Old St Labs |
| Public Sector | 3 of 17 — Fast Data Science, Transparity, Nebuli |
| Manufacturing | 3 of 17 — N-iX, Marionete, Opinov8 |
| Legal | 1 of 17 — Softblues |
Most common services offered by London SaaS & B2B agencies
These 17 SaaS & B2B agencies most commonly offer:
- AI Development14 of 17 — Fast Data Science, Elsewhen, N-iX, Transparity, +10 more
- AI Consulting14 of 17 — Fast Data Science, Elsewhen, N-iX, Transparity, +10 more
- AI Agents8 of 17 — N-iX, Transparity, Softblues, Hexploits, +4 more
- Generative AI6 of 17 — Elsewhen, N-iX, iCentric Agency, Nebuli, +2 more
- AI Automation6 of 17 — Transparity, Found, iCentric Agency, Softblues, +2 more
- AI SEO3 of 17 — Found, NOVOS, ClickSlice
Frequently asked questions — SaaS & B2B in London
- How much do SaaS & B2B AI agencies in London charge?
- Of the 17 SaaS & B2B AI agencies on this page, 14 publish complete hourly rate ranges. They range from €20 to €260, with a median around €65. Across the register, rated agencies in London bill €65–120/hr (20 rated). 8 agencies operate under €100/hr: N-iX, Marionete, Softblues, Hexploits.
- Which are the top-rated SaaS & B2B AI agencies in London?
- Based on our editorial scoring (portfolio quality, business credibility, and case study depth), the top-ranked SaaS & B2B AI agencies in London are Fast Data Science, Elsewhen, N-iX. See the full review on each agency's profile.
- What other industries do London SaaS & B2B agencies serve?
- Beyond SaaS & B2B, the most common cross-industry experience among these agencies is FinTech (9 of 17 agencies). Notable examples include Elsewhen, N-iX, Transparity.
- How recent are these SaaS & B2B AI agency reviews?
- 16 of the 17 agencies on this page have been editorially reviewed between Aug 6, 2026 and Sep 24, 2026 — the most recent being ClickSlice. See our review methodology for how scores are calculated.
- What's the smallest team size available for saas & b2b in London?
- Fast Data Science, Nebuli, Hexploits are the boutique studios (under 10 people) on this page, ideal for projects needing senior-level attention without large-team overhead.
Local Insight
SaaS & B2B AI Agencies in London
Software companies buy AI differently from the enterprises around them: the system usually ships inside a product other people pay for, so it has to survive its own users. The agencies here sit at different points of that. Hexploits engineers the platform itself — for swarmd.ai it built a multi-protocol agent relay, a gateway across model providers and a tenant-aware control plane, nine microservices into production, with the client keeping the codebase. Elsewhen works on product and platform for technology companies including Google and Spotify, and its published AI work is measured in booking revenue and reclaimed project timeline. iCentric builds multi-tenant platforms, including an agentic content-management product where clients manage a site through an assistant. The page has since widened past pure engineering: Fast Data Science does language work for the recruitment platform CV-Library, Nebuli builds knowledge systems, and NOVOS, Found and ClickSlice arrive from the demand side, selling AI-search visibility to software companies rather than building their products. Three more engineering firms have joined since: Opinov8 with an agent deployment platform, Pixelette Technologies from computer vision and data automation, and Old St Labs from the product-studio end.
Read that split first, because it is two markets on one page. The question that separates the builders is ownership after handover. Ask who runs the system in six months, whose cloud account it lives in, and what the release cadence looks like once the agency has gone.
Intro by Gabor Kiss, curator · How we rank
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