SaaS User Management and Access Control: Best Practices from Relevant

One weak permission model is all it takes. In its 2025 Data Breach Investigations Report, Verizon found that 22% of breaches started with stolen credentials, more than any other entry point. When a login is compromised, access control decides how far the attacker gets. That makes SaaS user management a security control, not a settings screen. Your product will be used in many ways by many customers, each needing different roles, and every one of those roles is a door you either lock or leave open.

Relevant is a SaaS engineering company with deep expertise in mobile and cloud-based application development. We help startups and enterprises build performant, secure, and scalable products. Our work spans retail, fintech, IoT, travel, and construction, so we design access models that hold up under real enterprise demands.

This guide walks through SaaS permissions management, the differences between RBAC, ABAC, and PBAC, and how to apply access control best practices that fit a zero trust world.

User management challenges in SaaS applications

Not all users are equal. Sometimes they want to perform actions that don’t match their roles. Depending on a customer’s niche, operational maturity, and organizational structure, they may need specific roles you never anticipated.

This creates the need for granular access control. Done well, it lets the software serve its purpose and meet complex enterprise authorization demands while ensuring application security, performance, and data integrity. Done poorly, it becomes the attack surface. If you want scalability and availability in distributed environments, designing your SaaS user account management should be one of your first concerns, not a late one.

User access control types: RBAC vs. ABAC vs. PBAC

When it comes to application access management, there are three approaches you can follow:

• RBAC, or the Role-Based Access Control model
• ABAC, or the Attribute-Based Access Control model
• PBAC, or the Permission-Based Access Control model

What is RBAC?

The RBAC model grants access to resources and actions based on a user’s role. This suits accounts that share an access level, such as regular users, group admins, and moderators. Update the policies and permissions for a role once, and every account with that role updates too. RBAC remains the foundation most teams start from because it is predictable, easy to audit, and simple to reason about.

How is role-based access control implemented?

Sometimes the same user needs several roles, or one permission has to apply across many roles. That flexibility can create complex structures. There are two common ways to manage SaaS users with RBAC:

• Granular RBAC lets certain users within an app instance create custom roles with unique permission sets. This meets each customer’s needs by adding granularity to access management.
• Role hierarchy builds a clear ranking of roles. A Team Lead sits above a Developer or QA engineer and holds permissions they don’t. Lower levels can’t reach certain permissions on their own but can be granted permanent or temporary access by a higher role.

RBAC aligns with the principle of least privilege, meaning every role holds the fewest privileges needed to do its job. That principle now sits at the center of zero trust security, where the rule is “never trust, always verify.” Least privilege also shrinks the blast radius of a compromised account and helps minimize web application vulnerabilities.

RBAC has a known limit. In large organizations the number of jobs keeps growing, and teams often add a new role for every edge case. That leads to role explosion: hundreds or thousands of roles that are hard to manage and become their own risk. This is where ABAC comes in.

What is ABAC?

In the ABAC model, a user’s role is just one attribute among several:

• User attributes, such as organization, username, role, email, and country of registration
• Environment attributes, such as the browser agent, device posture, or the origin of a request
• Resource attributes, such as who created a resource and when

With ABAC, an authorization engine evaluates every attribute before granting access or allowing an action. This lets you enforce context-aware rules, such as blocking access from an unmanaged device even when the user’s role would normally allow it, or requiring a VPN for remote workers reaching the corporate intranet. A standard RBAC setup can’t do that on its own.

Most teams don’t pick one model. A hybrid approach uses RBAC as the stable foundation and layers ABAC on top for real-time context. Roles set the baseline entitlements. Attributes decide whether a specific request passes at the moment it happens. That pairing keeps access both minimal and adaptive, which is exactly what zero trust demands.

What is PBAC?

With the PBAC model, permissions become separate entities, formed by abstracting the actions performed in the application. When a user requests an action, the system checks whether that user holds the matching permission.

These permissions are called grants. You can assign them directly to individual users or indirectly to user groups, though many implementations only honor permissions inherited from a group. This makes permission management far easier for heavily populated user groups inside large organizations.

B2B SaaS application user roles and permissions handling

You can segregate roles and permissions in SaaS products by structure, function, or geography. Here’s what each approach does.

Structure-based segregation

Here every customer assigns access rights based on its organizational structure. Picture several product teams inside the same app instance. One team has no QA engineer, so the Team Lead covers those duties. The permissions should adjust to match.

Function-based segregation

In the function-based approach, permissions follow the role within the organization. A Designer’s permission set differs from a Developer’s.

Geography-based segregation

This approach is the norm in multinational enterprises, where the organization spans many local instances with different role and permission sets.

Watch for over-permissioned accounts, where power roles carry superuser rights. Push those users toward less-privileged accounts for daily work. Standing privileged access is a favorite target: IBM’s Cost of a Data Breach Report 2025 put the global average breach at $4.44 million, and credential-driven attacks remain among the most common and costly paths in. 

On the other side sit under-permissioned users. Like temporary links to a Google document, these rights can be short-lived and scoped to a single action. Build a way to recognize the need for extra rights and grant them just in time. 

Finally, inactive users clog your database and widen the attack surface. Your SaaS database design should support automated deprovisioning after a set inactivity period, plus credential rotation. Automating onboarding and offboarding through SCIM makes this repeatable: when someone leaves the identity provider, their downstream SaaS access is revoked at once instead of lingering for months.

User handling on a multi-tenant application

One of the most common SaaS deployment models is multi-tenancy, where a single application, database, and infrastructure serve many customers, or tenants. Each tenant must manage its own users securely and reliably. Here are several best practices for doing so.

• Protect data from access outside the tenant. Every customer must define the scope of its users and roles and explicitly deny access to anyone outside the tenant.
• Delegate user management privileges. Customers run different user management policies, so delegate access management to admins within each tenant. This keeps tenant admins confined to their own data.
• Restrict admin rights. All tenants share the database, but no admin should ever reach another tenant’s data. Inside a tenant, an admin can manage permissions, users, and groups.
• Keep admin features simple to reach. Access management is complex enough, so make admin controls easy to find and use.

Finally, keep centralized logging, audit, and control across all tenants while letting tenant admins configure everything inside their own space. Enterprise buyers increasingly expect SSO through SAML or OIDC and automated provisioning through SCIM as table stakes, so plan for those standards early rather than bolting them on later.

Summary

A sound RBAC model is a vital step toward a stable, scalable, and secure SaaS application. Define the roles and their actions in advance, then allow custom roles and adjustable permission sets for unique customer demands. Layer ABAC-style context checks on top for zero trust, enforce least privilege everywhere, and automate the user lifecycle so access never outlives its purpose.

We know this well because Relevant has shipped many SaaS products for our clients. You’re welcome to read our case studies on end-to-end software development to see how we structured access control in practice. If you need help implementing user management in your SaaS, or developing a SaaS application from the ground up, contact us now.