An HRIS organizes employee information and the administrative processes that use it. Freelancer accounting software organizes the finances of an independent business, including client invoices, expenses, and payment records. Both may store names and dates, but an employee profile and a client or payee record describe different relationships.
For a solo consultant, the immediate need may be to bill a client and record business costs. For an agency employing staff, it may also be necessary to maintain manager assignments, personnel records, and employee requests. The agency can need both kinds of capability. Growth changes the work to manage; it does not turn bookkeeping into employee administration.