Why did ADP's operating expenses rise in Q4 2024?

ADP's operating expenses rose in Q4 2024 due to several key factors:

1. **Growth in Employer Services**: The increase in operating expenses can be attributed to the growth in the Employer Services segment. This segment reported revenues of $3.26 billion, representing a 7% change year-over-year.
2. **New Business Bookings**: The growth in new business bookings also contributed to the rise in operating expenses. New business bookings have been a driver of ADP's performance, indicating increased demand for its services.
3. **Pay-per-Control**: The growth in pay-per-control, which involves ADP handling payroll and other HR functions for clients on a per-control basis, has also contributed to the increase in operating expenses.
4. **Interest Income on Client Funds**: ADP has been earning higher interest income on client funds due to the high interest rate environment. Interest on funds held for clients increased by 17% to $277 million in Q4.

In summary, ADP's operating expenses rose in Q4 2024 due to growth in the Employer Services segment, new business bookings, pay-per-control, and higher interest income on client funds.