The Care Quality Commission (CQC) has begun a 'special programme' of 250 unannounced inspections of home care agency services.
The health watchdog says the work will inform how it regulates in other areas, including health visiting, district nursing, and community mental health services.
Philip King, CQC director of regulatory development, said: 'Home care is an area where it has been difficult for regulators to carry out unannounced inspections.
'With a large number of small providers, inspectors need to be sure that there are sufficient staff available at the agency's premises to assist with their questions without compromising care.'
As well as interviewing staff and managers of home care services, inspectors will accompany care workers on visits to people's homes, and go with managers on some of the spot checks carried out on services.
The extra inspections will run alongside the CQC's programme of planned inspections, under which it will inspect all 6,000 registered home care locations in England each year.
By law all NHS providers must register with the CQC, which has a range of legal powers at its disposal.