Eligible expenses are the costs a grant, voucher, or subsidy is allowed to fund under its official rules. In practice, this means the purchase must fit a defined category, use approved suppliers if required, and support a stated purpose such as cybersecurity, cloud migration, or resilience tooling. If a cost falls outside the list, it may be rejected even if it is useful to the business.
This matters in cyber security because funding often determines whether a company can afford controls like backup systems, endpoint protection, secure configuration, identity tools, or vulnerability management services. Attackers exploit weak budgets and rushed purchasing decisions, so organizations need to map each security need to an expense that is both technically effective and program-compliant. Good eligibility checks prevent waste, speed up procurement, and make sure public support is spent on controls that actually reduce risk.