The verdict in three sentences
A SaaS specification in 12 sections, with user stories and acceptance criteria, is the only way to get three truly comparable quotes. In 2026, a B2B SaaS platform costs EUR 40,000 to 150,000 (about USD 43,000 to 162,000) depending on the multi-tenant architecture and the complexity of subscription billing, with a 4 to 9 month timeline. Having an agency write the document costs EUR 2,000 to 6,000, under 5 % of the budget it protects.
The 12-section template
A product manager who sends a 3-page brief to three vendors gets bids at EUR 45,000, 90,000 and 140,000 that cannot be compared. Each vendor filled the gaps with its own assumptions. The template below sets those assumptions for everyone.
| No. | Section | Expected content |
|---|---|---|
| 1 | Context and goals | Business problem, target users, quantified success metrics |
| 2 | Personas and roles | Customer admin, end user, vendor super-admin |
| 3 | Functional scope | Module list, prioritised with MoSCoW |
| 4 | User stories | "As a… I want… so that…", 40 to 120 stories |
| 5 | Acceptance criteria | Given/When/Then for each priority story |
| 6 | Multi-tenant architecture | Shared database, schema per tenant or dedicated database |
| 7 | Billing and subscriptions | Plans, trials, usage-based pricing, VAT, Stripe or other |
| 8 | Integrations | SSO, public API, webhooks, third-party tools |
| 9 | Non-functional requirements | Performance, uptime, GDPR, security, accessibility |
| 10 | Design and UX | Existing mockups, brand guidelines, responsive |
| 11 | Schedule and budget constraints | Target date, envelope, milestones |
| 12 | Response format | Quote format, selection criteria, calendar |
Sections 6 and 7 drive most of the price variance. Left vague, one vendor prices a shared database and simple monthly payments, another full isolation and usage-based billing.
User stories and acceptance criteria: the anti-drift tool
A user story describes a need from the user's point of view; the acceptance criterion describes how to verify it is delivered. Example: "As a customer admin, I want to invite a colleague by email so that they can access our workspace." Criterion: "Given a logged-in admin, when they enter a valid address, then an invitation expiring in 72 h is sent and appears in the pending invitations list." This level of detail lets the vendor estimate each story in points or days, and lets you control acceptance testing.
2026 estimate by architecture
Budget depends mainly on two choices: the level of data isolation between customers and billing complexity.
| Configuration | Multi-tenancy | Billing | 2026 budget | Timeline |
|---|---|---|---|---|
| Simple MVP | Shared database, tenant filtering | 2 to 3 monthly Stripe plans | EUR 40,000 to 60,000 | 4 to 5 months |
| Standard SaaS | Shared database, row-level security | Plans, free trial, annual, coupons | EUR 60,000 to 90,000 | 5 to 6 months |
| Advanced SaaS | Schema per tenant | Usage-based, seats, EU VAT | EUR 90,000 to 120,000 | 6 to 8 months |
| Enterprise SaaS | Dedicated database per key account | Invoiced deals, SAML SSO, public API | EUR 120,000 to 150,000 | 7 to 9 months |
| Specification written by an agency | Workshops, stories, criteria | 25 to 60 page deliverable | EUR 2,000 to 6,000 | 2 to 4 weeks |
| Hosting and operations | Cloud, monitoring, backups | Recurring | EUR 300 to 2,000/month | Recurring |
To compare bids, ask every vendor for the same grid: estimate per module, assumptions made, day rate, number of days, warranty and maintenance terms. A gap above 30 % on the same module almost always signals a diverging assumption to clarify.
Mini case study
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Julie, product manager at a Lyon software company launching a fleet management SaaS for SMEs, consults three vendors with a 4-page brief. Quotes range from EUR 48,000 to 135,000. She invests EUR 4,500 in a 40-page specification (85 user stories, sections 6 and 7 settled: shared database with row-level security, per-seat billing). The new quotes narrow to EUR 78,000 to 92,000. Choosing the EUR 82,000 bid, she mainly avoids the usual drift: on a poorly specified project, change requests add 20 to 35 % to the budget, so EUR 16,000 to 29,000 saved for EUR 4,500 invested.
FAQ
How much does a B2B SaaS platform cost in 2026?
Between EUR 40,000 and 150,000 depending on multi-tenancy, billing and integrations. An MVP starts around EUR 40,000; an enterprise SaaS with SSO and a public API reaches EUR 150,000.
How many user stories should we plan?
From 40 for an MVP to 120 for a full platform. Beyond 150, split the project into several releases.
Should an agency write the specification?
It helps if you lack an experienced product manager. The EUR 2,000 to 6,000 cost is usually offset by 20 to 35 % fewer change requests.
How long does it take to launch a B2B SaaS?
Four to 9 months depending on configuration. An MVP on a shared database ships in 4 to 5 months, an enterprise version in 7 to 9 months.
What should the GDPR section contain?
EU data residency, the processor agreement (Article 28), retention periods and a per-customer export or deletion procedure. Budget EUR 3,000 to 8,000 for these features.
Let's scope your project. Send us your current document, even partial, and we will complete it with this template and return an estimate between EUR 40,000 and 150,000 with a 4 to 9 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.
