The verdict in three sentences
For a London software publisher that wants to resell its tool to 30 networks under their own brand, building a white-label multi-tenant SaaS architecture costs GBP 80,000 to 160,000 in 2026. The key items are per-client data isolation, custom domains, theming and per-tenant billing. With hosting at GBP 300 to 900 a month, a 75% gross margin is achievable from around twenty active clients.
What each multi-tenant building block costs
A tool designed for one client does not become multi-tenant by copying the database. Authentication, data partitioning, customization and billing all need rethinking without breaking the existing product.
| Building block | Role | Indicative price 2026 (GBP) |
|---|---|---|
| Data isolation (schema per tenant or PostgreSQL RLS) | No leakage between networks | 18,000 to 36,000 |
| Custom domains and automatic SSL | app.client-network.co.uk | 7,000 to 14,000 |
| Theming: logo, colors, branded emails and PDFs | True white label | 11,000 to 21,000 |
| Per-tenant billing (Stripe Billing, quotas) | Subscriptions, tiers, invoices | 12,000 to 27,000 |
| Super-admin console (create, suspend, support) | Managing the 30 networks | 11,000 to 23,000 |
| Roles and SSO per tenant (SAML, Microsoft Entra ID) | Required by large networks | 9,000 to 18,000 |
| Refactoring, regression tests, security audit | Non-regression, penetration test | 12,000 to 21,000 |
| Total project | Delivered in 4 to 6 months | 80,000 to 160,000 |
Three architectures, three cost profiles
The isolation model drives hosting cost, the security your clients perceive and ease of maintenance.
| Criterion | Shared database + RLS | Schema per tenant | Database per tenant |
|---|---|---|---|
| Development cost | Lowest | Medium | Highest |
| Hosting for 30 tenants | GBP 300 to 450/month | GBP 400 to 600/month | GBP 700 to 900/month and up |
| Isolation as seen by a large account | Fair | Good | Excellent |
| Schema updates | One migration | 30 scripted migrations | 30 scripted migrations |
| Client export or offboarding | Filtered query | Schema export | Database copy |
| Best for | Small homogeneous networks | Most B2B publishers | Banking, healthcare networks |
For 30 mid-sized networks, schema per tenant usually offers the best balance. A hybrid approach also works: dedicated databases for the two or three largest clients, schemas for the rest.
Obligations not to overlook
In white label, your client is the data controller toward its users and you are the processor under UK GDPR. Plan a data processing agreement, UK or EU hosting, per-tenant backups and a tested restore procedure. Franchise and healthcare networks often require an annual penetration test, budgeted at GBP 5,000 to 10,000. Cyber Essentials Plus certification also helps when selling to public-sector-adjacent networks.
Mini case study
Thomas runs a London publisher of appointment management software, used so far by a single driving school network. He targets 30 networks (driving schools, training centers, service agencies) at GBP 1,500 a month each, i.e. GBP 540,000 of annual revenue at full load.
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The multi-tenant build is priced at GBP 120,000. Annual direct costs include hosting (GBP 600 a month, GBP 7,200), maintenance (GBP 4,000 a month, GBP 48,000), Stripe (about 1.5% of revenue, GBP 8,100) and a support specialist at GBP 70,000 loaded. Total: GBP 133,300, a gross margin of 75%. With a gradual ramp-up (10 networks in year one, 30 in year two), payback lands around 18 to 20 months.
FAQ
How much does a white-label multi-tenant SaaS cost in London?
Plan GBP 80,000 to 160,000 in 2026 to convert an existing tool, depending on isolation model and SSO. A multi-tenant SaaS built from scratch typically starts around GBP 140,000.
What hosting should I plan for 30 clients?
GBP 300 to 900 a month on a UK or EU cloud region, depending on architecture. Cost per tenant drops below GBP 25 a month with schema per tenant.
Can each network have its own domain?
Yes. Custom domains and SSL certificates are handled automatically, with a GBP 7,000 to 14,000 budget for that block.
How long does the conversion take?
4 to 6 months, with a first pilot tenant migrated in month three to validate isolation and billing.
How should networks be billed?
Stripe Billing handles subscriptions, user tiers and compliant invoices. A common model combines a GBP 800 to 2,500 monthly fee with a per-active-user surcharge.
Let's scope your project. Tell us about your tool, the number of networks you target and your security requirements, and we will price the multi-tenant architecture between GBP 80,000 and 160,000 with a 4 to 6 month plan. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
