1. Purpose

The Service Account Register is a centralized record of non-human identities used by applications, services, automation, scripts, integrations, cloud workloads, CI/CD pipelines, databases, and other technical processes.

It helps the organization:

• Identify all service accounts.
• Record why each account exists.
• Assign a responsible owner.
• Document systems and resources accessed.
• Control privileges.
• Track credentials and authentication methods.
• Monitor service-account activity.
• Review service accounts periodically.
• Identify dormant or unnecessary accounts.
• Support secure rotation and revocation.
• Provide audit evidence.

Core Principle

Every service account should have a defined purpose, accountable owner, minimum required privileges, protected credentials, appropriate monitoring, periodic review, and a controlled lifecycle.

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2. Scope

The register may include:

• Application service accounts
• Database service accounts
• Cloud service identities
• AWS IAM roles
• AWS service-linked identities where relevant
• CI/CD service accounts
• Deployment identities
• Backup service accounts
• Monitoring identities
• Integration accounts
• API identities
• Automation accounts
• Scheduled-task accounts
• Bot/service identities
• Machine identities
• Workload identities
• Third-party integration identities

The register should cover production, development, testing, staging, and other relevant environments.

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3. Service Account Register – Master Template

Field	Description
Service Account ID	Unique register identifier
Account Name	Technical account/identity name
Account Type	Service/Application/API/Workload/etc.
Purpose	Business/technical reason
Application/Service	Application using the identity
Environment	Production/Test/Development
Cloud Provider	AWS/Azure/GCP/Other
Cloud Account/Subscription	Relevant account
Resource/System	Resource accessed
Owner	Accountable business/technical owner
Technical Custodian	Person/team managing it
Business Owner	Business accountability where applicable
Privilege Level	Standard/Privileged
Permissions	Key permissions granted
Information Accessed	Data/resources accessed
Information Classification	Public/Internal/Confidential/Restricted
Authentication Method	Role/Token/Certificate/Key/etc.
Credential Storage	Approved storage location
Credential Rotation	Rotation requirement
Last Rotation	Date
Next Rotation	Date
Interactive Login	Yes/No
MFA/Equivalent Control	Applicable protection
Network Restriction	Relevant restriction
Logging	Enabled/Disabled/N/A
Monitoring	Enabled/Disabled/N/A
Start Date	Creation date
Expiry Date	If applicable
Last Used	Last known activity
Last Review	Last review date
Next Review	Next review date
Status	Active/Disabled/Expired/Removed
Related Risk ID	Risk reference
Related Change ID	Change reference
Evidence	Evidence location
Remarks	Additional information

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4. Example Service Account Register

ID	Account	Purpose	System	Owner	Privilege	Status
SA-001	svc-backup	Database backup	AWS	IT/Cloud	High	Active
SA-002	svc-deploy	Application deployment	CI/CD	DevOps	High	Active
SA-003	svc-monitoring	Monitoring integration	Security Platform	Security	Medium	Active
SA-004	svc-reporting	Generate scheduled reports	Reporting App	Application Owner	Medium	Active
SA-005	svc-payment	Payment gateway integration	Payment Platform	Finance/IT	High	Active

These are example records and should be replaced with actual organizational identities.

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5. Service Account Types

Use standardized categories.

Type	Example
Application Account	Application connects to database
Service Account	Automated business/technical service
API Identity	System-to-system API authentication
CI/CD Identity	Automated deployment
Backup Identity	Backup process
Monitoring Identity	Monitoring/logging integration
Integration Identity	Third-party integration
Cloud Workload Identity	AWS/Azure/GCP workload
Database Identity	Application/database connection
Automation Identity	Scheduled script or automation
Emergency Service Identity	Emergency technical process

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6. Service Account Ownership

Every service account should have an accountable owner.

Recommended ownership fields:

• Service Account Owner
• Application Owner
• Technical Custodian
• Business Owner where applicable
• System/Cloud Owner

The owner is responsible for ensuring that the service account:

• Has a valid business/technical purpose.
• Has appropriate permissions.
• Is reviewed.
• Has protected credentials.
• Is removed when no longer required.

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7. Business Purpose

The purpose should explain why the identity exists and what it does.

Good example

Used by the CI/CD pipeline to deploy approved application builds to the AWS production environment.

Poor example

Deployment account.

The purpose should be specific enough for an independent reviewer to determine whether the account is still necessary.

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8. Service Account Lifecycle

A service account should follow a controlled lifecycle:

Business/Technical Need

↓

Risk Assessment

↓

Request

↓

Approval

↓

Create

↓

Assign Owner

↓

Grant Minimum Required Access

↓

Secure Credentials

↓

Test

↓

Monitor

↓

Review

↓

Rotate/Modify

↓

Disable

↓

Remove

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9. Service Account Creation

Before creating a service account, document:

• Purpose
• Application/service
• Owner
• Technical custodian
• Environment
• Required permissions
• Information/resources accessed
• Authentication method
• Credential storage
• Rotation requirements
• Logging requirements
• Monitoring requirements
• Expiry date where applicable
• Risk considerations

Creation should be approved by the appropriate system/application/cloud owner.

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10. Least Privilege

Service accounts should receive only the permissions necessary to perform their approved function.

For example:

Backup Service

Required:

• Read approved backup source
• Write to approved backup destination

Should not automatically receive:

• Full administrator privileges
• User-management permissions
• Security-policy modification
• Unrelated production resources

The permissions should be reviewed against the actual function of the service.

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11. Privileged Service Accounts

Some service accounts require elevated privileges.

Examples:

• Production deployment identity
• Infrastructure automation
• Backup administration
• Security monitoring
• Database administration
• Cloud infrastructure automation

For privileged service accounts:

• Document the business/technical justification.
• Minimize permissions.
• Restrict scope.
• Protect credentials strongly.
• Enable logging where technically possible.
• Monitor activity where appropriate.
• Review more frequently based on risk.
• Define ownership and accountability.

Privileged service accounts should also be referenced in the organization’s privileged-access records where applicable.

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12. Authentication Methods

Preferred authentication mechanisms should be selected based on the technology and risk.

Examples include:

• Workload identity
• Federated identity
• IAM role
• Managed identity
• Short-lived token
• Certificate
• API token
• Secret/key where unavoidable

Where the platform supports short-lived or role-based authentication, this may reduce the risk associated with long-lived credentials.

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13. Credential Management

Service-account credentials should be protected using approved mechanisms.

Examples:

• Secrets Manager
• Key management system
• Enterprise password vault
• Approved secret-management platform
• Cloud-native identity mechanisms

Do not store secrets in:

• Source-code repositories
• Plain-text configuration files
• Spreadsheets
• Email
• Chat messages
• Tickets
• Documentation
• Service Account Register

Important

The register should record where the credential is securely stored, not the actual password, token, private key, or secret.

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14. Credential Rotation

Where credentials are used, define appropriate rotation requirements.

Record:

• Rotation method
• Rotation frequency
• Last rotation
• Next rotation
• Rotation owner
• Evidence

Example:

Account	Credential	Last Rotation	Next Rotation	Method
SA-001	API Token			Automated
SA-002	Deployment Credential			Secrets Manager
SA-003	Certificate			Certificate Management

Rotation frequency should be based on risk, technology, contractual requirements, and organizational policy rather than assuming one universal period.

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15. Interactive Login

Service accounts should generally be designed for automated use rather than interactive human login.

Record:

Interactive Login: Yes / No

If interactive login is required:

• Document the reason.
• Restrict the account appropriately.
• Apply strong authentication where supported.
• Monitor use.
• Review necessity periodically.

Unexpected interactive use of a service account should be investigated where appropriate.

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16. Shared Service Accounts

Avoid using a service account as a substitute for individual user accountability.

For example, avoid:

Multiple administrators directly using admin-service.

Prefer:

Individual User → MFA/SSO → Approved Role → Service/Resource

If a shared technical identity is unavoidable:

• Document the reason.
• Assign an owner.
• Restrict access.
• Record authorized users.
• Monitor use where possible.
• Review periodically.
• Define credential-handling requirements.

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17. AWS Service Account / Workload Identity Example

For an AWS SaaS environment, service identities may support:

• Application workloads
• CI/CD
• Backup
• Monitoring
• Security automation
• Data processing
• Infrastructure automation
• Third-party integrations

Example:

Service Identity	Purpose	AWS Resource	Access
svc-app-prod	Application workload	RDS/S3	Required application permissions
svc-deploy-prod	CI/CD deployment	ECS/Lambda	Deployment permissions
svc-backup	Backup	AWS Backup/RDS	Backup permissions
svc-monitoring	Monitoring	CloudWatch	Monitoring permissions

Where practical, use AWS roles/workload identities rather than long-lived IAM access keys.

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18. CI/CD Service Accounts

CI/CD identities can have significant production access and should receive particular attention.

Review:

• Repository
• Pipeline
• Deployment target
• Permissions
• Environment
• Secrets
• Approval requirements
• Production deployment restrictions
• Logging
• Owner

Example:

GitHub Actions → Federated Identity → AWS Role → Approved Deployment Resources

This can reduce dependence on long-lived static credentials.

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19. Database Service Accounts

For database identities, document:

• Database
• Application
• Environment
• Purpose
• Database role
• Tables/schemas accessed where appropriate
• Read/write permissions
• Owner
• Credential storage
• Rotation
• Logging

Avoid giving an application database account unrestricted database administrator privileges unless specifically justified.

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20. API and Integration Accounts

For system-to-system integrations, record:

• Integration name
• Sending system
• Receiving system
• Service identity
• Data transferred
• Information classification
• API permissions
• Authentication method
• Credential storage
• Third party
• Contract/security requirements
• Owner
• Expiry/review date

Example:

SaaS Application → Payment Gateway API → API Identity → Payment Processing

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21. Third-Party Service Identities

Where a supplier requires a technical identity:

Record:

• Supplier
• Integration
• Purpose
• Data/resource accessed
• Permissions
• Owner
• Contract reference
• Security assessment
• Expiry/review
• Credential management
• Incident contact

Third-party service identities should be reviewed when the supplier relationship, integration, or business purpose changes.

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22. Service Account Access Review

During a review, verify:

• Account still exists.
• Purpose remains valid.
• Owner is current.
• Application/service still exists.
• Permissions remain necessary.
• Privileges are appropriate.
• Credentials are protected.
• Rotation is current.
• Logging is enabled where appropriate.
• Monitoring is appropriate.
• Last-use information is available where technically possible.
• Account is not dormant.
• Expiry has not passed.
• Related risks are addressed.

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23. Dormant Service Accounts

Identify service accounts that:

• Have not been used for an extended period.
• Belong to retired applications.
• Belong to old integrations.
• Have no identifiable owner.
• Have no documented purpose.
• Have expired projects.
• Are associated with deprecated environments.

Possible actions:

Validate → Retain → Restrict → Disable → Remove

Do not automatically delete an apparently dormant service account if doing so could disrupt a critical service. Investigate dependencies first.

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24. Service Account Decommissioning

When a service account is no longer required:

1. Confirm the service/application is no longer dependent on it.
2. Identify related credentials.
3. Disable the identity.
4. Revoke tokens/keys/certificates where applicable.
5. Remove permissions.
6. Remove secrets from approved secret stores where appropriate.
7. Check integrations and automation.
8. Monitor for unexpected failures.
9. Update the register.
10. Retain evidence.

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25. Emergency Service Accounts

Emergency identities should be separately identified.

Record:

• Purpose
• Owner
• Emergency use conditions
• Authorized personnel
• Authentication controls
• Credential storage
• Monitoring
• Review frequency
• Last test
• Last use
• Evidence

After emergency use:

Use → Investigate → Review Activity → Rotate Credentials if Applicable → Close Emergency Access

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26. Service Account Monitoring

Where technically feasible, monitor:

• Authentication activity
• Privilege use
• Unexpected source locations
• Unexpected resources
• Failed authentication
• Unusual volume
• Interactive login
• Permission changes
• Credential changes
• New access
• Unexpected API activity

Examples in AWS environments may include relevant CloudTrail, CloudWatch, and security-monitoring records.

Monitoring requirements should be proportionate to the account’s risk.

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27. Service Account Change Management

Changes should be controlled when they affect:

• Permissions
• Owner
• Application
• Environment
• Authentication method
• Credential
• Resource scope
• Cloud account
• Integration
• Privilege level

Example:

Change Request → Risk Assessment → Approval → Change → Testing → Verification → Register Update

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28. Service Account Risk Assessment

Service-account risk may increase when:

• It has administrative privileges.
• It accesses production.
• It accesses Confidential/Restricted information.
• It uses long-lived credentials.
• It has broad permissions.
• It has no owner.
• It is externally accessible.
• It supports a critical service.
• It connects to third parties.
• It cannot be effectively monitored.

Risk treatment may include:

• Reduce privileges
• Restrict network access
• Replace static credentials
• Use workload identity
• Implement secrets management
• Add monitoring
• Rotate credentials
• Add expiry
• Separate environments
• Disable unnecessary access

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29. Service Account Register Review Record

Account ID	Review Date	Owner	Purpose Valid	Permissions Appropriate	Credential Secure	Monitoring	Action
SA-001			Yes	Yes	Yes	Yes	None
SA-002			Yes	No	Yes	Yes	Reduce Access
SA-003			No	N/A	Yes	Yes	Disable

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30. Service Account Exceptions

Document exceptions such as:

• Long-lived credential
• Excessive privilege
• Interactive login
• Shared technical identity
• Missing automated rotation
• Legacy application limitation
• Missing monitoring
• No supported MFA mechanism

Exception ID	Account	Exception	Reason	Risk	Compensating Control	Owner	Expiry

Exceptions should have an owner and, where appropriate, an expiry/review date.

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31. Audit Evidence

Evidence may include:

• Service Account Register
• Cloud IAM records
• AWS IAM/Identity Center records
• IAM role policies
• Secrets Manager records
• Key-management records
• CI/CD configuration
• Application configuration
• API integration records
• Access approvals
• Change records
• Credential rotation records
• CloudTrail/security logs
• Monitoring alerts
• Access reviews
• Decommissioning records
• Exception records
• Risk assessments

Never use audit evidence repositories as a reason to expose actual credentials or secrets.

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32. Startup-Friendly Implementation

A startup can implement this without creating a complex identity-management platform.

Minimum Service Account Register

At minimum, record:

1. Service Account ID
2. Account Name
3. Purpose
4. Application/System
5. Environment
6. Owner
7. Technical Custodian
8. Permissions
9. Authentication Method
10. Credential Storage
11. Last Rotation
12. Last Review
13. Status

Then progressively add:

• Risk
• Monitoring
• Expiry
• Data classification
• Third-party relationship
• Cloud account
• Related change
• Evidence

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33. Relationship with Other ISMS Documents

The Service Account Register connects with:

Identity Management Policy

↓

User Account Management Procedure

↓

Identity Register

↓

Service Account Register

↓

Access Control Matrix

↓

Privileged Access Register

↓

Access Review Report

↓

Change Management

↓

Risk Register

↓

Incident Management

↓

JML / Offboarding

This provides traceability from the identity to its purpose, access, risk, review, and eventual removal.

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34. Quick Audit Checklist

• All service accounts identified
• Each account has a unique identifier
• Purpose documented
• Owner assigned
• Technical custodian assigned
• Application/system identified
• Environment identified
• Permissions documented
• Privileged accounts identified
• Authentication method documented
• Credentials securely stored
• Credential rotation addressed
• Interactive login assessed
• Logging/monitoring assessed
• Third-party identities identified
• Dormant accounts reviewed
• Expiry dates used where appropriate
• Periodic review completed
• Unnecessary accounts disabled/removed
• Evidence retained
• Exceptions documented

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35. Final Audit Trail

For any service account, an auditor should be able to trace:

Service Account

→ What is it?

→ Why does it exist?

→ Which application uses it?

→ Who owns it?

→ What can it access?

→ Why does it need that access?

→ How is it authenticated?

→ Where are its credentials protected?

→ Is its activity monitored?

→ Has it been reviewed?

→ Has its access changed appropriately?

→ What happens when the service is retired?

→ Is evidence available?

Final Principle

Know the service account. Know what it does. Know who owns it. Give it only the access it needs. Protect its credentials, monitor it appropriately, review it regularly, and remove it when the service no longer requires it.