SaaS Development Company in London

A London SaaS platform can be a lean launch or a procurement-ready system, and the diligence is the difference: a scoped SaaS MVP at London rates, a mid-market platform with enterprise SSO via SAML and SCIM, role-based access control, audit logging, FCA-aligned compliance modules, and Cyber Essentials Plus accreditation, or full enterprise SaaS with multi-region deployment, ISO 27001 certification support, SOC 2 Type II programme, and FCA authorisation alignment. Scope drivers include multi-tenant architecture, authentication with SSO-ready scaffolding, Stripe Billing, a baseline admin console, and a SOC 2 readiness gap analysis. London rates reflect the senior engineering market and IR35 off-payroll overhead. Most engagements qualify partially under the April 2024 merged R&D scheme, and IP may attract Patent Box at 10 percent.

We choose between three tenancy models based on the regulatory and commercial profile. Row-level security on a shared Postgres schema is the default for early-stage SaaS where blast radius is acceptable and cost matters, with tenant_id enforced in policies rather than application code. Schema-per-tenant suits mid-market platforms where some customers want logical isolation without the operational overhead of separate databases. Database-per-tenant is reserved for FCA-authorised, NHS, or government customers who contractually require physical isolation, with separate KMS keys and isolated backups per tenant. We document the choice in the Statement of Applicability and the master services agreement so procurement and security functions at City and Canary Wharf buyers have a clear answer during due diligence.

Yes. UK and European enterprise buyers in 2026 will not sign a master services agreement without at least one credible certification path. Cyber Essentials Plus is the entry standard, achievable inside three months on a properly hardened cloud stack, and effectively mandatory for public sector and most enterprise procurements. SOC 2 Type II takes nine to twelve months of operating evidence after readiness, and is the standard US enterprise expectation. ISO 27001:2022 is the European preference and pairs naturally with UK GDPR and ICO obligations. We architect for all three from day one, instrument the controls in code, integrate Drata, Vanta, or Secureframe for continuous monitoring, and hand over a Statement of Applicability your CISO or vCISO can defend to an auditor without rewrites.

Billing for London SaaS hits multiple tax regimes. UK VAT at 20 percent applies to UK customers, EU VAT under the One Stop Shop regime applies B2C to EU consumers, and B2B EU sales use the reverse charge with a valid VIES VAT number. US sales tax via Avalara or Stripe Tax handles the US nexus complexity. We default to Stripe Billing or Chargebee, both of which handle VAT and EU MOSS inside the platform with the right configuration, and we wire usage metering through StripeMeter, OpenMeter, or a custom event pipeline when consumption pricing matters. Dunning, smart retries, SCA challenges for European cards, and Mandate management for SEPA and Bacs Direct Debit are all standard. Revenue recognition under IFRS 15 is wired into your accounting system through Stripe Revenue Recognition or NetSuite.

Yes. We have shipped platforms for FCA-authorised payment institutions, e-money institutions, and investment firms. Architecture aligns with FCA PS21/3 operational resilience requirements, including identification of important business services, impact tolerance setting, and severe-but-plausible scenario testing. PSD2 strong customer authentication is implemented via FIDO2 passkeys with permitted exemptions. Senior managers and certification regime accountabilities are reflected in the platform's audit log and approval workflows. We also handle FCA Connect submissions for change-in-control and variation of permissions where the platform itself triggers regulatory notification. For PRA dual-regulated clients, we extend the same posture to SS2/21 outsourcing and third-party risk management.

We default to AWS eu-west-2 (London) primary with eu-west-1 (Ireland) as a regulated secondary, Azure UK South (London) and UK West (Cardiff), or GCP europe-west2 (London) for application and data tiers. EU tenants who require EU-only residency get an eu-central-1 (Frankfurt) or eu-west-3 (Paris) tenant shard with no UK replication. NHS tenants stay inside UK regions under the NHS DSPT. Cross-border transfers to the US rely on the UK Extension to the EU-US Data Privacy Framework or Standard Contractual Clauses with a Transfer Risk Assessment. KMS keys are region-bound. Backups are encrypted, region-bound, and time-limited. We document residency in the Statement of Applicability, the Data Processing Agreement, and the customer-facing trust centre.

A typical London B2B SaaS MVP takes twelve to twenty weeks from kickoff to first paying customer, assuming the product surface is scoped and the integration list is bounded. Week 1 to 4 is discovery, tenancy model selection, and Figma. Week 5 to 14 is core platform build, authentication, billing, and the first vertical workflow. Week 15 to 18 is hardening, SOC 2 and Cyber Essentials readiness, observability, and security scanning. Week 19 to 20 is launch with pilot customers and the trust centre live. Reaching the SOC 2 Type II and ISO 27001 milestones adds nine to twelve months of operating evidence after launch, which we run in parallel with feature development rather than as a separate audit project.

Codazz delivers through our Edmonton and Chandigarh engineering hubs as a fully outsourced service rather than seconding contractors into your IR35 chain. That keeps the engagement squarely outside the off-payroll working rules, because the contract is for the delivery of defined outputs against a fixed fee rather than for the supply of named individuals working under your direction and control. Where a client genuinely needs an embedded contractor (rare, usually for technical leadership transitions), we provide guidance on Status Determination Statements aligned with HMRC CEST and case law, but the default model is fully outsourced delivery. This matters most for medium and large UK clients who carry the IR35 determination liability under the 2021 reforms.