SaaS · Definition
What tenants are, how separation works, the trade-offs and how to plan multi-tenancy on Bubble.io.
Last updated: October 2026. Written by Athar Ahmad, Certified Bubble.io Developer and Tech Architect, Simple Automation Solutions.
Quick answer
Multi-tenant architecture is a way of building software in which many customers (tenants) share one running application while each tenant’s data is kept separate. Single-tenant gives each customer a separate instance. Multi-tenancy lowers cost and speeds updates and onboarding, but a flaw in access rules can expose one tenant’s data to another. On Bubble.io it is usually built with a Company data type and privacy rules, tested with accounts from multiple tenants.
Key takeaways
- Multi-tenant = shared application, separated data; single-tenant = separate instance per customer.
- Separation depends on tenant-linked data and access rules enforced in the data layer.
- Main risks: data leakage, noisy neighbours, limited customisation, compliance demands.
- On Bubble: a Company data type plus privacy rules, tested with multiple tenants.
- Decide tenants, roles, shared data and offboarding in the PRD.
In this guide
What is multi-tenant architecture?
Multi-tenant architecture is a way of building software in which many customers, called tenants, share one running application and one underlying system, while each tenant’s data is kept separate and invisible to the others. Most SaaS products work this way. The opposite approach, single-tenant architecture, gives each customer their own separate instance of the software.
Single-tenant vs multi-tenant
| Single-tenant | Multi-tenant | |
|---|---|---|
| Structure | A separate application and database per customer | One application and shared infrastructure for all customers, with separated data |
| Cost to run | Higher, since each customer needs their own resources | Lower per customer, since resources are shared |
| Updates | Must be applied to every instance | Applied once for everyone |
| Customisation | Easier to customise deeply per customer | More limited, usually through settings and configuration |
| Isolation | Strong, by physical separation | Depends on how well data access is designed and enforced |
| Onboarding a customer | Slower: set up a new instance | Faster: create a new tenant account |
| Typical use | Highly regulated or very large customers with special needs | Most SaaS products and portals |
How does tenant separation work?
In a multi-tenant system, every piece of customer data is linked to the tenant that owns it, and the system enforces that a user can only see data from their own tenant. In practice this means:
- A tenant or account record for each customer organisation.
- Every data record linked to its tenant, for example each project, document or invoice belongs to a tenant.
- Users belong to a tenant, with roles inside it, such as owner, admin and member.
- Access rules enforced in the data layer, so a query can never return another tenant’s records.
- Testing with accounts from two tenants, trying to reach each other’s data.
How does this work in Bubble.io?
In a Bubble.io app, a common pattern is a Company or Account data type, with each User linked to a Company and each business record linked to a Company. Privacy rules on every data type then grant access only when the record’s Company matches the current user’s Company. The shared database holds all tenants, and the rules keep them apart. Getting this wrong is the most serious risk in a multi-tenant app, so rules need to be designed up front and tested with multiple accounts. See our guide to multi-tenant architecture on Bubble.io, our security guide and database design mistakes.
What are the benefits of multi-tenancy?
- Lower cost per customer.
- One codebase or app to maintain and improve.
- Faster onboarding.
- Easier to deliver improvements to everyone at once.
- Aggregate insight across customers, where permitted.
What are the risks and trade-offs?
- Data leakage. A flaw in access rules can expose one tenant’s data to another.
- Noisy neighbours. Heavy use by one tenant can affect performance for others.
- Limited customisation. Deep per-customer changes are harder.
- Compliance concerns. Some customers or regulations demand separation or specific data locations.
- Shared outages. A problem affects every tenant at once.
Which should you choose?
| If… | Consider |
|---|---|
| You are building a typical B2B SaaS or portal | Multi-tenant |
| Each customer needs deep, bespoke customisation | Single-tenant, or a hybrid |
| A few large customers demand isolated environments | Multi-tenant for most, with dedicated instances for those few |
| Regulation requires strict data separation or location | Seek advice; consider single-tenant |
| You want to launch quickly and cheaply | Multi-tenant |
What should you plan before building?
- Who is a tenant: a company, a team, an individual or a branch?
- What roles exist inside a tenant?
- What data is shared across tenants, such as templates or reference lists?
- How will plans, limits and billing attach to tenants?
- How will you offboard a tenant and delete or export their data?
- What isolation do your customers’ contracts and regulations demand?
These decisions belong in the PRD. Our Discovery Sprint ($345, delivered in 24 hours, credited toward the build) covers them. Builds start at $3,500 and typically launch in 2 to 6 weeks.
Frequently asked questions
What is a tenant in SaaS?
A customer organisation or account that uses the shared application, with its own separated data.
What is the difference between single-tenant and multi-tenant?
Single-tenant gives each customer a separate instance. Multi-tenant serves many customers from one shared application with separated data.
Is multi-tenant architecture secure?
It can be, when access rules are enforced in the data layer and tested thoroughly. The main risk is a flaw that exposes one tenant’s data to another.
Can you build a multi-tenant SaaS on Bubble.io?
Yes. A common approach links users and records to a Company data type and uses privacy rules to keep tenants apart, with careful testing.
When do customers need single-tenant?
When regulation, contracts or very specific customisation demand separation. Many products use multi-tenant for most customers and dedicated setups for a few.
Planning a SaaS with several customer accounts?
Email us your idea. We will design the tenant structure, roles and access rules into the plan.
Athar Ahmad, Certified Bubble.io Developer and Tech Architect, Simple Automation Solutions
About Simple Automation Solutions (SA Solutions)
Simple Automation Solutions is a Bubble.io development studio led by Athar Ahmad, a Certified Bubble.io Developer and Tech Architect. It builds web and mobile apps, client portals and SaaS products for founder-led businesses such as law firms, accounting firms, boutique agencies and consultants. Services include a free 30-minute Idea Audit, a $345 Discovery Sprint (a Product Requirements Document delivered within 24 hours, credited toward the build) and builds starting at $3,500. Website: sasolutionspk.com.
