The Ultimate Guide to Access Control Systems: Types, Uses & Best Practices

How Access Control Systems Protect Your Facilities, Systems, and Data

Access control determines who may access a resource, when access is permitted, and under what conditions. In today’s organizations, this means managing both who can enter your buildings and who can log into your digital systems and access sensitive information.

While physical and digital access need different tools and know-how, it’s important not to treat them as separate issues. A smart approach to access control brings everything together: physical badges, digital logins, employee roles, permissions, and processes for joining or leaving the company.

In this article, we explain:

• How physical and digital access control systems work
• The different types of access control solutions
• Common access control models and when they are used
• How access control supports physical security, cybersecurity, and compliance
• Best practices for managing access across your organization

Continue reading to learn how Solid Security | Technology helps businesses protect their people, property, systems, and information.

Key Takeaways

• Access control includes both physical access to facilities and digital access to systems and information.
• Physical access control systems use credentials, readers, controllers, permissions, and locking hardware to manage entry to secured areas.
• Digital access controls use identities, authentication methods, roles, and permissions to protect networks, applications, files, and data.
• Coordinating physical and digital access can reduce security gaps during hiring, employee role changes, vendor visits, and employee departures.
• Solid Security | Technology provides specialized expertise across both areas, helping organizations build a more comprehensive security strategy.

 

What Is Access Control?

Access control is the process of determining who or what may access a physical location, digital system, or information resource. That could be a building, an office, a network, an app, or a confidential document.

Access control generally falls into two specialized areas:

Physical Access Control

Physical access control manages entry to buildings, rooms, gates, elevators, and other secured areas. These systems may use:

• Access cards and key fobs
• Mobile credentials
• PIN codes
• Biometric identifiers
• Electronic locks
• Door controllers
• Access schedules
• Visitor and vendor credentials

Physical access control lets you decide who can go where, at what time, and which areas are off-limits.

Digital Access Control

Digital, or logical, access control manages access to systems and information. These controls may include:

• User accounts and digital identities
• Password policies
• Multi-factor authentication
• Application and file permissions
• Network access controls
• Role-based permissions
• Administrative privileges
• Account provisioning and deprovisioning

Digital access control ensures employees and trusted partners can access the systems and data they need without granting broader access than their responsibilities require.

How Physical Access Control Systems Work

A physical access control system replaces or supplements traditional mechanical keys with electronically managed credentials.

When a person presents a card, key fob, mobile credential, PIN, or biometric identifier, the reader sends the credential information to the system controller. The controller evaluates the credential based on the person’s assigned permissions, the door being accessed, the time of day, and other configured rules.

If the request is approved, the controller signals the locking hardware to release the door. Some systems record the event, creating an audit trail that administrators can review.

A properly designed system may include:

• Credential readers
• Door controllers
• Electronic locking hardware
• Door-position sensors
• Request-to-exit devices
• Power supplies and backup power
• Access management software
• Alarm and event notifications

All these parts need to work together. For example, a card reader won’t keep a building secure if the door doesn’t latch or doesn’t let you know if it’s left open.

Modern systems make it easy to issue or change access, set schedules, disable lost cards, or shut off access when someone leaves, without replacing locks or attempting to recover every physical key.

When access control is integrated with video surveillance, administrators can review corresponding footage for events such as a forced-open door, denied credential, or unusual activity. This provides valuable visual context when investigating an incident..

How Digital Access Control Works

Digital access control determines whether a user, device, or system may access a network, application, file, or other information resource.

The process typically includes two distinct steps:

Authentication

Authentication confirms that a user is who they claim to be. Common authentication methods include:

• Passwords and passphrases
• Authenticator applications
• Hardware security keys
• One-time verification codes
• Biometric identifiers

Authorization

Authorization determines what the authenticated user is permitted to access or do.

For example, an employee may be authorized to access a scheduling application but not payroll records. A department manager may be able to approve transactions, while a standard user may only be permitted to view information.

Strong digital access controls help organizations apply the principle of least privilege, which means users receive only the access required to perform their responsibilities.

 

Types of Physical Access Control Systems

The right physical access control solution depends on the facility’s size, the number of locations, security requirements, existing infrastructure, and daily operations.

Card and Key-Fob Systems

Cards and key fobs provide a familiar and scalable way to manage entry. Credentials can be assigned to individual users, placed in access groups, and disabled when lost or no longer required.

The security of a card or fob system depends in part on the credential technology used. Modern encrypted credentials generally provide stronger protection against duplication than older proximity technologies.

Mobile Access Control

Mobile credentials allow authorized users to access doors using a compatible smartphone or mobile device. They can reduce the need to issue physical credentials and may simplify credential distribution for employees, vendors, and temporary users.

PIN-Based Access

Keypads allow users to enter a numeric code to request access. PINs may be used alone or combined with a card, mobile credential, or biometric identifier for additional verification.

Shared PINs are generally less secure because they can be copied or distributed without authorization. Individually assigned credentials provide stronger accountability.

Biometric Access Control

Biometric systems use physical characteristics, such as fingerprints or facial features, to authenticate users.

Biometrics can provide greater assurance that the person presenting the credential is the authorized individual. They may be used alone or as part of a multi-factor process for higher-security locations.

Organizations considering biometrics should also evaluate privacy requirements, enrollment procedures, environmental conditions, user acceptance, and operational reliability.

Cloud-Based Access Control

Cloud-managed platforms allow authorized administrators to manage credentials, permissions, and activity from a web-based interface. These systems can be especially valuable for organizations with multiple locations or limited on-site administrative resources.

On-Premises Access Control

On-premises systems are managed through software and infrastructure located within the organization’s environment. They may be appropriate for organizations with specific network, operational, or security requirements.

Standalone and Networked Systems

A standalone system may be suitable for a single door or small facility. A networked system provides centralized management across multiple doors, buildings, or locations.

Types of Digital Access Controls

Organizations use several technologies and processes to manage digital access. The appropriate combination depends on the systems being protected, the sensitivity of the information, and the risks associated with unauthorized access.

Multi-Factor Authentication

Multi-factor authentication requires users to verify their identities using more than one type of authentication factor. It provides additional protection if a password is stolen or compromised.

Single Sign-On and Identity Management

Single sign-on and centralized identity-management platforms allow organizations to manage access to multiple applications through a common user identity. This can simplify account administration and help organizations apply access policies more consistently.

Role-Based Permissions

Role-based permissions assign access according to an employee’s responsibilities. This helps organizations avoid granting every user the same level of access.

Conditional Access

Conditional access policies evaluate factors such as the user, device, location, application, and level of risk before granting access. An organization may require additional verification or block access when a request does not meet established security requirements.

Privileged Access Controls

Privileged access controls limit and monitor administrative permissions. These controls are particularly important because administrator accounts can make systemwide changes and access sensitive information.

Guest and Vendor Access

Temporary and third-party accounts should be limited to the systems and information required for a defined purpose. Access should be reviewed regularly and removed when it is no longer needed.

Why Physical and Digital Access Should Be Coordinated

Physical and digital access controls protect different resources, but weaknesses in one area can undermine protections in the other. Coordination does not necessarily require physical and digital access controls to operate on a single platform. It means aligning policies, responsibilities, and access-management processes across systems that require different technologies and specialized expertise.

For example:

• A secured server room provides limited protection if former employees still have active administrative accounts.
• Multi-factor authentication cannot prevent an unauthorized visitor from entering a records room or accessing an unlocked workstation.
• A vendor may require temporary access to a mechanical room without receiving broader access to the building or company network.
• An employee changing departments may require updates to both door permissions and application access.
• A departing employee’s building credential and digital accounts should both be disabled promptly.

Organizations should coordinate physical and digital access during:

• Employee onboarding
• Promotions and role changes
• Department transfers
• Temporary assignments
• Vendor and contractor visits
• Employee terminations
• Lost or compromised credentials
• Security incident investigations

This coordination creates a more complete picture of who has access, why they have it, and whether that access remains appropriate.

How Access Control Supports Physical Security and Cybersecurity

Physical access control protects people, buildings, equipment, records, and other assets by limiting entry to authorized individuals.

Digital access control protects networks, applications, files, and sensitive information by limiting access to authorized users and systems.

Together, these controls can help organizations:

• Reduce unauthorized access
• Protect sensitive areas and information
• Create access logs and audit trails
• Investigate security incidents
• Manage employee and vendor access
• Improve accountability
• Support internal security policies
• Address applicable regulatory requirements

Access records should be interpreted carefully. A physical access system records the credential and door event, but it may not always prove who physically entered. Credential sharing, tailgating, and propped doors can still create risk.

Video surveillance, door-held-open alerts, visitor management, security awareness training, and properly maintained door hardware can provide additional protection.

Access Control and HIPAA-Regulated Organizations

Healthcare organizations and their business associates must consider how employees, vendors, and other individuals access facilities, systems, and electronic protected health information.

Physical safeguards may include controlling entry to areas containing:

• Paper or electronic medical records
• Servers and network equipment
• Workstations that access electronic protected health information
• Diagnostic equipment that stores or transmits patient information
• Other systems used to store, process, or access sensitive information

Technical safeguards may include:

• Unique user identities
• Multi-factor authentication
• Role-based permissions
• Audit logging
• Account lifecycle management
• Restricted administrative privileges
• Secure remote access

Physical and digital access controls can support an organization’s HIPAA compliance program, but no single product or installation makes an organization compliant. Compliance also depends on documented policies, risk assessments, employee training, procedures, monitoring, and ongoing management.

Access Control Best Practices

Apply the Principle of Least Privilege

Employees should receive only the physical and digital access required to perform their assigned responsibilities.

Access should not be granted simply because it may be convenient in the future.

Review Permissions Regularly

Organizations should periodically review physical credentials, user accounts, access groups, administrative privileges, and temporary permissions.

Reviews are especially important when employees change roles or departments.

Coordinate Onboarding and Offboarding

Create a consistent process for issuing and revoking physical credentials and digital accounts.

When an employee leaves the organization, access should be disabled promptly across all applicable systems.

Use Individual Credentials

Avoid shared cards, shared PINs, and shared user accounts whenever possible. Individual credentials create stronger accountability and more useful audit records.

Use Multi-Factor Authentication Where Appropriate

High-risk systems and sensitive areas may require more than one authentication method.

For example, a user may be required to present a card and enter a PIN, or enter a password and approve a login through an authentication application.

Monitor Exceptions and Unusual Activity

Review events such as:

• Repeated denied access attempts
• Doors forced open
• Doors held open
• Login attempts from unusual locations
• Access outside normal hours
• Unexpected administrative changes
• Inactive accounts that remain enabled

Maintain Systems and Door Hardware

Access control effectiveness depends on the proper functioning of software, controllers, readers, locks, sensors, networks, and power supplies.

Doors should close and latch correctly, and systems should be updated and tested regularly.

Plan for Safe Egress and Emergency Operations

Physical access control systems must be designed in accordance with applicable fire, building, and life-safety requirements.

The ability to restrict entry should not interfere with safe occupant egress or required emergency procedures.

How Solid Delivers Comprehensive Access Protection

Solid Security | Technology brings specialized expertise to two distinct but interconnected areas of access control.

Solid Security

Solid Security designs, installs, and supports physical access control systems that help organizations manage entry to buildings, doors, gates, and secured areas.

Our security specialists can help evaluate:

• Door and locking hardware
• Credential technologies
• Access schedules and permission groups
• Multi-location management
• Video surveillance integration
• Visitor and vendor access
• Door monitoring and event notifications
• Future scalability

Solid Technology

Solid Technology helps organizations protect digital identities, networks, applications, and sensitive information.

Our technology specialists can help evaluate:

• User identity management
• Multi-factor authentication
• Role-based permissions
• Microsoft 365 access controls
• Network and application security
• Employee onboarding and offboarding
• Administrative privileges
• Access monitoring and audit readiness

Together, these capabilities enable Solid to help clients identify gaps that may be overlooked when physical security and cybersecurity are evaluated in isolation.