Choosing between a traditional VPN and zero trust network access (ZTNA) is less about selecting the newer label and more about matching access controls to the systems, users, devices and risks your business actually has. This guide gives small businesses and IT teams a repeatable way to compare both models, estimate implementation effort and decide whether a phased or hybrid approach is more practical.
Overview
A business VPN usually creates an encrypted connection between a user’s device and a private network. After authentication, the user may be able to reach a broad range of internal systems, depending on the VPN configuration and network segmentation. This model remains useful where staff need network-level access, applications are hosted on internal servers, or older systems cannot work with modern identity-aware controls.
ZTNA takes a different approach. Rather than placing a user inside the network, it grants access to specific applications or services after checking identity, device state and relevant access policies. The user may be allowed to reach a single internal web application without receiving general access to neighbouring systems. This application-level model can reduce unnecessary exposure, but it normally requires better identity management, application visibility and policy administration.
In a practical ZTNA vs VPN comparison, neither option automatically wins. A VPN may be simpler for a small team with a limited set of internal resources. ZTNA may be a better fit where users work from varied locations, contractors need narrow permissions, or the organisation wants access decisions to depend on more than a password. Many businesses use both during a transition.
For background on broader business VPN considerations, see our remote access security checklist for small businesses. If remote desktop is involved, avoid treating a VPN as a reason to expose RDP directly to the internet; review the guidance on securing remote desktop.
How to estimate
Use a simple decision score rather than comparing product features in isolation. Give each factor a score from 1 to 5 for your current environment:
- Network-level access required: 1 means users need only a few applications; 5 means they need several internal networks, protocols or legacy services.
- Application readiness: 1 means most systems can support identity-aware access; 5 means important systems depend on network location, fixed routes or older clients.
- Identity and device maturity: 1 means you already manage central identity, multi-factor authentication and device security; 5 means these controls are inconsistent or incomplete.
- Need for least-privilege access: 1 means broad access is acceptable for the work; 5 means users, contractors and suppliers need tightly separated permissions.
- Operational capacity: 1 means the IT team can manage new policies and integrations; 5 means a simple, familiar deployment is essential.
These scores are not a security rating. They are a way to expose trade-offs. A high network-access score and high application-readiness score point towards a hybrid evaluation. A high least-privilege score combined with strong identity foundations supports investigating ZTNA. A high legacy-dependency score and limited IT capacity may favour a carefully hardened VPN in the short term.
You can also estimate the total effort using four categories:
- Technology: licences, gateways, connectors, endpoint agents, identity integrations and any required network changes.
- People: design, testing, policy creation, support and user training.
- Migration: application discovery, pilot groups, documentation and running old and new access methods together.
- Risk reduction: the value of narrower permissions, stronger authentication, better device checks and improved access visibility.
Do not compare only subscription costs. A lower licence price can still produce a higher overall cost if deployment requires extensive redesign or creates support work. Conversely, a more capable control may be uneconomical if the business cannot operate it consistently.
Inputs and assumptions
Before choosing a secure remote access model, document the inputs that will drive the decision. Start with an inventory of applications, not just servers. Record where each application is hosted, who uses it, which protocols it requires, whether it supports modern authentication and whether it contains sensitive information.
Next, map user groups separately. Employees, administrators, contractors and third-party support staff rarely need identical access. Note the duration of access, working locations, device ownership and approval requirements for each group. Short-term contractor access is often a useful test case because it reveals whether your controls can grant and remove narrow permissions without creating permanent network reach.
Assess device posture realistically. A policy that requires managed, encrypted and patched devices is only useful if the business can verify those conditions. Decide how you will handle personal devices, mobile workers and devices that cannot run an endpoint agent.
Finally, identify operational assumptions:
- Who approves access and reviews it?
- How quickly can access be revoked?
- How are failed logins, unusual locations and compromised devices investigated?
- What happens when the identity provider, VPN gateway or ZTNA connector is unavailable?
- Which logs are retained, and can the team use them during an incident?
For a VPN, include configuration details such as split tunnelling, DNS handling, multi-factor authentication, route scope and the kill switch behaviour of managed clients. For ZTNA, include connector placement, application segmentation, identity-provider dependencies, device checks and policy exceptions. Security controls should be tested rather than assumed; a VPN privacy and connection audit can help structure testing of a VPN deployment.
Worked examples
Example 1: Small office with legacy systems
A 20-person company has an internal file server, accounting software and a few older applications. Staff need access to several internal resources, while the IT team has limited time for application-by-application integration. In this case, a business VPN may be the practical starting point. The priority should be strong authentication, restricted network routes, separate administrator access, device controls and regular review of who still needs access.
ZTNA can still be evaluated for web applications and contractor access, but replacing the VPN immediately may add migration risk without solving the legacy dependency.
Example 2: Distributed team using modern applications
A growing company uses cloud services and a small number of internally hosted web applications. Employees work from home, offices and shared locations. Different teams need different applications, and administrators want access decisions tied to identity and device condition. This environment is a stronger candidate for ZTNA because application-level policies may reduce the need for broad network access.
The estimate should include identity clean-up, multi-factor authentication, device-management coverage, application connectors and time for pilot testing. A VPN may remain necessary for a legacy database or administrative workflow.
Example 3: Hybrid access during a transition
A business cannot replace all internal systems at once. It can place modern web applications behind ZTNA while keeping a restricted VPN for legacy services. To control complexity, define which users use which path, avoid duplicate permissions, monitor both systems and set a target date for reviewing the remaining VPN dependencies.
This approach is not automatically safer. Two access systems mean two policy sets, two sets of logs and two possible sources of configuration error. The hybrid model should therefore have clear ownership and a documented reason for every exception.
When to recalculate
Revisit the decision whenever the inputs change, rather than treating it as a one-time technology purchase. Recalculate after an acquisition, office closure, major shift to remote work, new compliance requirement, identity-platform change or migration of a sensitive application. Also review the model after a security incident, unexplained access event or repeated user-support problem.
Pricing and licensing should be checked whenever the number of users, devices, applications or connectors changes. Do not assume that a per-user model and a gateway-based model will scale in the same way. Record the assumptions behind your estimate so that a future review can distinguish genuine cost changes from changes in scope.
Use this practical review checklist:
- Update the application and user inventory.
- Remove accounts, routes and policies that are no longer required.
- Re-score network access, application readiness, identity maturity, least privilege and operational capacity.
- Compare technology, people and migration effort with the expected reduction in unnecessary access.
- Test authentication, revocation, logging, device checks and recovery procedures.
- Choose a next step: retain and harden the VPN, expand ZTNA, or run a controlled hybrid pilot.
The best secure remote access model is the one your team can configure correctly, monitor continuously and change when the business changes. Treat ZTNA vs VPN as an ongoing access-design decision, not a contest between product categories.
