Single-tenant vs multi-tenant

In a single-tenant deployment one customer has a dedicated instance of the software and data store; in a multi-tenant deployment many customers share the same instance, separated logically.

Part of the Learn hub and the customer data glossary.

What it means in practice

Tenancy describes how many customers share a running instance. In a multi-tenant system, customers share compute, application code and often databases, separated logically by tenant identifiers, access rules and sometimes per-tenant encryption keys. It is efficient to run, upgrades reach everyone together, and a flaw in isolation can touch more than one customer. In a single-tenant system each customer has its own instance, database and often its own network and keys, which allows its own region, upgrade window and tighter isolation, usually at higher cost.

Tenancy is not the same as who operates the system or where it runs. A single-tenant instance can be vendor-operated, so the vendor's staff keep administrative access, or customer-operated in your own account. Ask who holds administrative credentials and encryption keys, where backups live and how support access is granted.

Neither model is inherently compliant or non-compliant. Twilio says business associate agreements for its Segment SaaS service are available on its Business tier (and as an add-on per its plan table), and HCL's customer data platform lists both multi-tenant and single-tenant cloud options. The test is contract, controls and evidence, not the label.

Example (health insurer): a payer wants a dedicated environment for member engagement data. Single-tenant gives it separate infrastructure and keys, but if the vendor's staff can access member data, a business associate agreement is still needed.

Related terms

• Self-hosted customer data platform (CDP): customer-operated deployment.
• Bring your own cloud (BYOC): vendor-managed in your account.
• Customer-managed keys: per-customer encryption control.
• Data residency: location, a separate question.
• Packaged customer data platform (CDP): usually multi-tenant.

Where it matters

• On-premise, private cloud and self-hosted customer data platforms: the complete guide: tenancy options compared.
• Composable vs packaged vs private customer data platforms: where tenancy fits.