HR Software Security: What to Look For
HR software handles some of the most sensitive personal data in any organisation: employee salaries, bank account details, personal addresses, health information, disciplinary records, and performance assessments. The security requirements for this data are more stringent than for most business software categories, and the consequences of a data breach — legal liability, reputational damage, loss of employee trust — are significant. Evaluating the security posture of an HR software vendor should be a substantive part of the procurement process, not a checkbox on the contract.
The certifications that provide the most relevant assurance for HR software vendors are ISO 27001 (information security management), SOC 2 Type II (service organisation controls for security, availability, and confidentiality), and GDPR compliance certifications for European markets. ISO 27001 and SOC 2 Type II are independently audited: the certifications are granted by an accredited third party that has reviewed the vendor's security controls against defined standards. Vendors who claim "compliance with ISO 27001 principles" without holding the certification are a different category from those who have undergone the independent audit.
Encryption standards matter at the data level. Employee personal data should be encrypted at rest (in the database) and in transit (in all communications between the user and the platform). The encryption standard should be AES-256 for data at rest and TLS 1.3 for data in transit. Vendors who cannot provide clear answers about their encryption standards, or who describe them in vague terms, warrant further scrutiny.
Access controls determine who within the vendor organisation can access customer data. A vendor's customer data should be accessible to as few people as possible within the vendor's own team, with access logging that records who has accessed which customer data and when. For sensitive HR data — salary records, health information, disciplinary records — the access controls should be more restrictive than for general product telemetry. Vendors who have clear data access policies, with named personnel authorised to access customer data and documented justification requirements, provide stronger assurance than those with broad internal data access.
Data residency is an increasingly important consideration, particularly for European organisations under GDPR. Where is customer data stored? Is it stored in data centres in the customer's jurisdiction or transferred to another jurisdiction? If transferred, what legal mechanism governs the transfer? Vendors who can provide clear answers about data residency and transfer mechanisms, and who offer data residency options for customers with specific requirements, are better positioned for organisations with GDPR data localisation requirements.
The incident response process is a security indicator that is rarely discussed in vendor evaluations but is highly relevant. How will the vendor notify customers in the event of a security incident? What is the timeline for notification? What information will be provided? What remediation is the vendor responsible for? Vendors with documented incident response procedures and historical incident disclosures demonstrate more mature security practices than those who have never discussed what happens when something goes wrong.
Mellow's security architecture is built around the requirements of employment data as a sensitive data category: AES-256 encryption at rest, TLS 1.3 in transit, role-based access controls within customer organisations, and data residency in European data centres for European customers. ISO 27001 certification and SOC 2 Type II audit reports are available on request. The data processing agreement details the security obligations that Mellow assumes as a data processor, providing the legal clarity that GDPR-regulated customers require.