In the USA it has more be more related to the computerized systems of payroll. We’d like to believe these are advanced, but not quite so yet. Especially when we consider merger and acquisitions, sub-divisions, multi-site companies, multi-banking accounts depending on how old a company is, etc. We also have many companies in the USA with different pay scales, pension plan formulas, executive benefit compensation, all sorts of deduction options, pre-tax benefit deductions, multi-bank account deposit options, and so on. Payroll can be super complicated when it comes to the major role it plays in administration. To answer your question, it would be less expensive in the long run to activate all payroll once a month, but transferring to such a cycle may not make sense to some in terms of cost. There is also lots of testing that has to happen when a company changes these systems to make sure nothing goes wrong which adds to risk, scope of project, costs, etc. Payroll is part of Human Capital/Human Resources and in the USA this department is usually seen as overhead. Not a profit center. Non-profit centers are usually asked to keep costs down - so modernization/changing of payroll cycles would usually be at the bottom of a list. It’s kind of a if not broken don’t fix it.