Outsourcing accounting can be done in different ways: getting a freelance accountant, hiring an accounting agency, and business process outsourcing. Depending on their services, each option fits with a specific situation on hiring.
Businesses hire a freelance accountant or bookkeeper for one-off or annual consolidation of their accounts and tax filing. They hire accounting firms for quarterly auditing and compliance of tax returns. A BPO company, meanwhile, is fit for monthly regular accounting duties.