What Does It Cost to Build a SaaS Product in 2026? Multi-Tenancy Costs Explained
One request has become noticeably more common in the past two years: a company that has done well in a niche wants to turn the management software it has used internally for years into a product it can sell to peers. In other words, turn a system into a SaaS, and the first number they ask about is SaaS product development cost.
These companies usually benchmark against what the internal system cost, then get startled by the SaaS quote, which is often two to three times higher. Here is where that money goes, and whether any of it can be saved.
1. The real difference: one customer versus a hundred
Building an internal system for one enterprise lets you assume a great deal: everyone follows the same process, there is one copy of the data, accounts are created by an administrator, upgrades happen at weekends, and a phone call gets a problem fixed.
Selling SaaS to a hundred companies invalidates every one of those assumptions. Each company runs a different process, data must never leak across tenants, signup must be self-service, upgrades cannot cause downtime, and customers must be able to diagnose issues themselves. Four assumptions collapse, and four new cost blocks appear.
2. Block one: multi-tenant architecture, 50,000 to 150,000 RMB
This is the foundation of SaaS and the least skippable part of any SaaS product development cost estimate, plus the biggest divergence from an internal system. The core question is how to store data: a separate database per tenant, or one shared schema distinguished by a tenant identifier.
Separate databases isolate most thoroughly and limit blast radius, suiting a small number of customers with large data volumes, but operational overhead is high: backups, upgrades and migrations across a hundred databases is manual labour. A shared schema with a tenant column is cheap to operate but unforgiving: one query that forgets the tenant filter is a data breach.
Most real projects settle on a hybrid: shared tables with isolation for core business data, dedicated databases for sensitive cases or large accounts. Decide this early; changing it mid-project is effectively a rebuild.
Beyond data, configuration itself must become multi-tenant. Every customer wants a different logo, field naming, approval flow and reporting definition, and these must be configurable rather than hard-coded. This layer is routinely underestimated and typically accounts for about a fifth of total development effort.
3. Block two: subscription and billing, 40,000 to 120,000 RMB
An internal system never collects money. SaaS must. And charging is more complex than it appears: how to structure plans, per-seat versus usage-based pricing, trial periods, proration on upgrade or downgrade, suspension for non-payment, refunds.
Technically this means payment integration, an order and subscription state machine, invoice generation, and retry logic for failed auto-renewals. Usage-based pricing additionally requires metering and reconciliation: the monthly bill you send a customer must be something they can verify themselves, or you are in for endless disputes.
Invoicing and tax are mandatory too. Enterprise customers in China almost always require a fapiao, which means integrating an invoicing provider, handling red-letter reversals and applying different tax rates, none of which exists in an internal system.
4. Block three: self-service signup and permissions, 30,000 to 80,000 RMB
Internal accounts are created by administrators; SaaS accounts are created by customers. Registration, email or SMS verification, company verification, inviting colleagues and initial role assignment must all run automatically, with anti-abuse controls against spam and repeated trial signups.
The permission model must also be rebuilt. Internal systems typically have fixed roles; SaaS must let each customer define roles and permission combinations, and must distinguish platform administrators from tenant administrators. Get this wrong and every later feature forces a change to the permission tables.
5. Block four: open capability and reliability, 50,000 to 150,000 RMB
When you sell to peers, customers will demand integration with their own ERP, with WeCom, with the other tools they already use. That requires open APIs, key management, call quotas and rate limiting, and documentation.
Reliability requirements differ entirely. An internal outage affects one company. A SaaS outage affects a hundred customers and can trigger refund demands the same day. That means multiple environments, canary releases, monitoring and alerting, log search, backup and recovery drills. Quotes often fold this into a single "operations" line, but it is mandatory engineering effort.
6. Three tiers and their prices
Tier one, single-tenant but replicable, 200,000 to 400,000 RMB, the cheapest answer to the SaaS product development cost question. Technically still one system per customer, but with a standardised deployment pipeline so the second and third customer can be spun up quickly. Suits a customer count under ten with wide variation in requirements. Cheapest to build, but you accept manual operations.
Tier two, standard multi-tenant, 400,000 to 700,000 RMB. One system genuinely serving many customers, with data isolation, configurability and self-service signup in place. Suits a product already stabilised with dozens of customers ahead.
Tier three, multi-tenant plus billing and open platform, 600,000 to 1,000,000 RMB. Tier two plus subscription billing, invoicing, open APIs and an operations stack that supports scale. Suits companies treating SaaS as their main business.
7. The first-year budget is not just development
Servers and databases scale with customer count: a few thousand RMB monthly early on, typically ten to twenty thousand once past a hundred customers.
Third-party services -- SMS, email, object storage, content moderation, monitoring -- total 1,000 to 5,000 RMB monthly.
Compliance: SaaS collecting company or personal information needs filings and privacy documentation, and customers in regulated sectors such as finance and healthcare will require you to support their own security assessments.
Acquisition and onboarding, the most overlooked line. Selling to peers is not a matter of publishing a listing: it needs sales, a demo environment, and per-customer initialisation and training. The common practice is to reserve 30 to 50 percent of development cost for acquisition and onboarding in year one.
Maintenance and iteration, at 15 to 20 percent of development cost annually. SaaS cannot stop iterating; a product that pauses loses competitiveness within six months.
8. When not to build SaaS
If the total addressable customer base is under twenty, each requiring deep customisation, or you do not intend to build a sales and support team, SaaS is probably not worth it. In that case, keep the system as a repeatable delivery offering and sell projects one at a time: more predictable revenue, far less investment.
The cost structure of SaaS makes it a long commitment: development is only the entry ticket, and the annual operations, iteration and acquisition are the real spend. Understand that before deciding to shift from doing projects to building a product.