ISO 27001:2022 Annex A 5.16 Identity & Access Management Explained

In this guide you will learn how to implement ISO 27001 Annex A 5.16 Identity Management and pass your audit from ISO 27001 Lead Auditor Stuart Barker – author of the ultimate ISO 27001 Toolkit.

ISO 27001 Annex A 5.16 is an ISO 27001 control that requires an organisation to mange the full life cycle of identities.

Key takeaways

• Digital identities can be both human and system based
• More that one entity can access an identity
• Identities should be managed for their entire life cycle.

Purpose & Definition

The purpose of ISO 27001 Annex A 5.16 Identity Management is a preventive control that ensures the unique identification of individuals and systems accessing the organisations information and other associated assets and to enable appropriate assignment of access rights.

The ISO 27001 standard defines ISO 27001 Identity Management as:

The full lifecycle of identities should be managed.

ISO/IEC 27001:2022 Annex A 5.16 Identity Management

FREE ISO 27001 Annex A 5.16 Training Video

In this free training video you will learn How to implement ISO 27001 Identity Management (Annex A 5.16) and Pass Your Audit.

Implementation Guide

What is Identity Management?

Identity management is an evolution of user access management that covers the entire lifecycle of digital identities for all entities.

Identities are used to access data and resources.

It is a framework of policies, process and technologies to ensure that the right entities have the right access to the right resources.

Human and non human identities

Human and non human identities are no longer distinct from each other. For practicable terms they are treated the same.

Implement an approval process for creating or revoking identities

You will want a process that covers the approval for the creating, revoking and deletion of identities. Think in terms of user accounts and system accounts. We cannot go around creating these willy nilly, allowing them to do what ever they like and then forgetting about them. Your process can be simple but the driving principle is the person making the request cannot be the person that approves it. This is part of segregation of duty and clearly, hopefully, is common sense. What ever the process is in terms of the technology that implements it, you should maintain and audit trail of the approvals. An example would be keeping copies of the email exchange, or the tickets that were raised in a ticketing system.

Consider perhaps that your processes may vary slightly or be tightened up a little in certain circumstances. Examples of this would be where third parties require accounts or identities to be created. Also an example would be super user and administrative identities.

Confirm the business requirement for creating an identity

For the creation of all identity types a business case and / or justification is documented and included in the approval process.

It is important to understand why you are creating an account or an identity. It will allow the person approving it to understand what and why they are approving as well as allow you to maintain some level of control in the technological Wild West that you no doubt have in place.

Particular attention should be given to admin accounts or accounts that have special powers. Not like superman. But like the kind that can cause significant harm or access everything.

Verify the identity of an entity before creating the virtual representation

In a world of zero trust, when an entity is created, modified or deleted both the requestor and the entity where relevant are appropriately verified and checked.

The standard doesn’t give much guidance on this and clearly it is going to be hard if not impossible to do for non human identities. It is a hang over from when they only worried about user accounts so they kept it. It does make sense for users and people so as part of the approval process, or for the human that requires the identity, verifying who they are and that they are who they say they are makes senses. There is a lot of phishing attempts made to get people to do things they would not normally do, including creating accounts, that bad guys then use to do you harm. I am not saying check passports and photo id but I am saying be sensible and do some level of check to satisfy yourself the person is who they say they are. Use common sense. If you get a request and it doesn’t feel right no one minds if you pick up the phone to check or ask their boss / others for extra verification.

Create the identity

This really should be done by someone that knows what they are doing. The identity is going to be used to access ‘stuff’ so it is probably a good idea at this stage to create the record of the identity and who it was assigned to. The identity is created and access granted. Default permissions are removed and modified to reflect the role based access or creation request. The user is informed via secure methods and default credentials are forced to be changed at the first opportunity.

Configure the identity and activate it

Again, this should be done by someone that knows what they are doing. It is easy to create accounts and identities but you really should have experience to understand what you have created and how to configure in a way that meets the approved request and the needs of the business rather than what ever the default system identity. Defaults are defaults and not designed to meet your specific needs.

It goes without saying – DO NOT USE DEFAULT IDENTITY PASSWORDS.

Did that really need saying? You would be surprised.

It is easy to Google what the default identities and passwords are for systems. Way too easy.

One person one ID

Where an identity is assigned to a human then it should be unique to that human so we know what that human did if things go wrong and we can control what the human has access to and can do. Through training and awareness based on having policies in place that tell people not to share login information and including the consequences of doing so.

Many persons one ID

The standard and common sense wants one human to one ID but it does allow for many people using one ID where they are required for business, operational needs and have appropriate documentation. Ensuring that approval processes account for shared identities and the sparing use of such identities in exceptional circumstances that are clearly documented.

Non Human IDs

As in the implementation guide above you will want an approval process for system and non human identities. You will also want some level of oversight of them. There is no guidance in the standard on what this means so I recommend having a periodic ( monthly ) review of all service accounts to make sure they are needed still and perhaps alternating with a check on the configuration of the ID and what it can do.

Remove old IDs

Processes such as the leaver process and off boarding as well as automated processes that create identities remove and or disable identities that are no longer required.

Reviews and audits are put in place to check that identities no longer required are handled appropriately in a timely manner and not left in systems.

You can only call something by one name

Identities are never duplicated, they are never copied to create new identities and the rule of one user, one entity to one ID is upheld where ever possible.

The standard doesn’t want you calling entities by different names with different names mapped. If your entity / server / laptop or what ever is called Brian then it is called Brian. It isn’t called Brian by IT but Anna by HR.

Logging, Monitoring and Reporting

The standard wants records of significant events on the use and management of identities and for that to be kept. This is actually a powerful statement and was a clause in its own right but logging and monitoring of identities and administrative actions is a must. It is just up to you to decide what ‘significant’ means.

I would not get carried away logging everything as you will never look at it but consult the norm for the systems you are using and think about things like

• failed log on attempts
• account creating
• account deletion

Events are determined as appropriate, considering creation, modification and deletion and those events once determined are recorded and those records are kept.

Identity Management Process

The identity management process is usually made up of the following process steps:

Request for the identity / access: the identity is requested by someone. This step usually includes a justification for the creation of the identity and access required.

Approval: the request is formally approved. This step is usually conducted by someone senior in the organisation in conjunction with the system and / or data owner.

Implementation: the identity is created and access granted. Default permissions are removed and modified to reflect the role based access or creation request. The user is informed via secure methods and default credentials are forced to be changed at the first opportunity.

Modification: following the structured approval process the identity is modified based on business need.

Destruction: when no longer required the identity is disabled and ultimately deleted.

Identity Management Principle

The principles on identity management are One User to One ID.

Access Control Policy Template

The access control policy sets our your approach to identity management.

How to implement ISO 27001 Annex A 5.16

Implementing ISO 27001 Annex A 5.16 is about establishing a definitive digital identity for every person or service that interacts with your systems. As a Lead Auditor, I want to see a seamless lifecycle where identities are verified at the start and revoked immediately at the end. Without a structured Identity Management process, your access controls are built on sand. Follow these ten steps to ensure your identity framework is audit-ready and technically robust.

1. Formalise the Identity Management Policy

Establish a documented policy that defines how identities are created, managed, and retired. This serves as your primary governance document for the entire identity lifecycle.

• Define clear roles and responsibilities for identity administrators and approvers.
• State the requirement for unique identifiers for every user and service entity.
• Prohibit the use of shared or generic accounts to maintain individual accountability.

2. Map Identities to the Asset Register

Treat digital identities as critical assets by including them in your Information Asset Register. This ensures that every identity has a clear owner and a defined business purpose.

• Categorise identities into types such as employees, contractors, and service accounts.
• Link identities to specific hardware or software assets they are permitted to access.
• Ensure the Register of Experts (ROE) documents who has the authority to manage these identities.

3. Implement a Rigorous Registration Process

Create a formal workflow for the registration of new identities. This prevents the “ad-hoc” creation of accounts that often leads to security vulnerabilities.

• Require a formal request from a department head or asset owner for every new identity.
• Integrate the identity request into your standard Joiner, Mover, Leaver (JML) process.
• Document the business justification for each identity created within your IAM system.

4. Verify Entity Identity Before Provisioning

Establish a standard for verifying the identity of a human or service before any digital credentials are issued. You must be certain that the entity is who they claim to be.

• Utilise government issued identification or validated HR records for human users.
• Implement technical verification for service identities or API keys.
• Maintain a record of the verification method used for audit evidence.

5. Provision Unique Identifiers

Assign a unique, non-reusable identifier to every entity. This is the foundation of accountability within your system logs and forensic capabilities.

• Ensure that usernames or IDs are unique across the entire organisational ecosystem.
• Implement a policy that prevents the immediate reuse of identifiers after an identity is retired.
• Sync identifiers across disparate systems using a Centralised Identity Provider (IdP).

6. Manage Authentication Information Securely

Establish secure protocols for the initial issuance and subsequent management of authentication secrets. The handover of initial credentials is a high-risk touchpoint.

• Use secure, out of band channels to deliver initial passwords or tokens.
• Force a password change upon the very first login attempt.
• Implement Multi-Factor Authentication (MFA) as a mandatory requirement for identity activation.

7. Automate the De-registration Process

Develop a process to revoke identities immediately when an individual leaves the organisation or a service is no longer required. Orphaned identities are a primary target for external threats.

• Connect your IAM system to HR triggers to ensure de-provisioning happens in real time.
• Set a hard limit, such as 24 hours, for the removal of all access after an employee departs.
• Ensure that de-registration also triggers the recovery of physical access tokens or keys.

8. Monitor Identity Lifecycle Changes

Implement logging and monitoring for every change made to an identity. This provides visibility into who modified an identity and why, which is crucial for compliance.

• Log all events related to identity creation, modification, and deletion.
• Protect identity logs from unauthorised modification or deletion to maintain audit integrity.
• Set up alerts for unauthorised attempts to create or modify privileged identities.

9. Perform Regular Identity Re-verification

Schedule periodic reviews to ensure that existing identities are still valid and that the verification status remains current. Identities should not exist indefinitely without re-validation.

• Conduct an annual review of all active identities against current HR and contractor lists.
• Verify that the “owner” of each service account still requires that identity to be active.
• Deactivate identities that have been inactive for a defined period, such as 90 days.

10. Audit the Identity Management System

Conduct regular internal audits of the identity management framework to ensure it operates as intended. This “Check” phase ensures your technical controls haven’t drifted from your policy.

• Sample new registrations to ensure the authorisation trail is complete.
• Test the leaver process to verify that accounts are truly disabled within the required window.
• Provide documented audit results as evidence for your ISO 27001 Stage 2 certification.

ISO 27001 Templates

How to pass the ISO 27001 Annex A 5.16 audit

To comply with ISO 27001 Annex A 5.16 Identity Management you are going to implement the ‘how’ to the ‘what’ the control is expecting. In short measure you are going to

• Implement a process for creating, updating and removing IDs
• Implement an approval process
• Include business case / justification in the approval process
• Have a HR leaver process that removes user IDS
• Regularly review accounts and identities
• Log and monitor activity

What the auditor will check

The audit is going to check a number of areas. Lets go through the most common

1. That you have not done something stupid

The auditor is going to check the rules, procedures and access control methodology and make sure you followed them. As with everything having documented evidence of anything you can is going to be your friend. So practical things like asset registers, access control procedures that you can evidence are in operation, reviews of access. Work through recent hires for example and ensure the processes were followed and look for the gotchas. Is there an approval audit trail. When you log into the system that was approved does the users access match what was requested.

The easiest win for an auditor is get you to show them the admin accounts on what ever system you are using and then explain the accounts that are in the admin group. 9 out of 10 times there are admin accounts in here you forgot about, are for people that left or you are unsure yourself what the account is. Instant problem. Check now.

2. That you have rules, processes and you have followed them and have trained people

This is obvious but they are going to look that you have documented what you say you do, that you follow it and that you have trained people. The biggest gotcha here is having people with accounts that have left. In other words you didn’t have or follow a leaver process and so people’s access remain even though their contract has ended.

3. Documentation

They are going to look at audit trails and all your documentation and see that is classified and labelled. All the documents that you show them, as a minimum if they are confidential should be labelled as such. Is the document up to date. Has it been reviewed in the last 12 months. Does the version control match. Doing anything else would be a massive own goal.

Top 3 Mistakes People Make and How to Avoid Them

The top 3 Mistakes People Make For ISO 27001 Identity Management are

1. People have left but they still have an account

Make sure that access to systems is up to date and that people or third parties that have left no longer have access or accounts.

2. Third parties have open access and account they do not need

Third parties should follow process and the process should be to grant access to them when the access required and remove it when it is not. It should not be open and continual access. Consider the example where you need a third party to fix something. You would grant access to allow the fix and then remove it. You would not have open ended access granted.

3. Your document and version control is wrong

Keeping your document version control up to date, making sure that version numbers match where used, having a review evidenced in the last 12 months, having documents that have no comments in are all good practices.

ISO 27001 Annex A 5.16 FAQ

Further Reading and Related ISO 27001 Controls

• ISO 27001 Annex A 5.18 Access Rights
• ISO 27001 Clause 6.1.3 Information Security Risk Treatment
• ISO 27001 Access Control Policy Beginner’s Guide

Matrix of controls and attribute values

Control type	Information security properties	Cybersecurity concepts	Operational capabilities	Security domains
Preventive	Confidentiality	Protect	Identity and access management	Protection
	Integrity
	Availability