Complaints recorded by Thames Valley Police increased by 6.5 per cent over the previous year, according to force figures.
The force handled 4,277 complaints in 2025/26, compared with 4,017 in 2024/25.
The local increase was smaller than the rise reported across England and Wales.
The Independent Office for Police Conduct received data from 43 forces covering April 2025 to March 2026, during which a national total of 108,897 complaints was logged.
This represented a 15 per cent increase from 2024/25 and the highest figure recorded since the watchdog began collecting and examining the information.
Poor service was the leading category nationally, accounting for 55 per cent of allegations.
Issues involving police powers and policies made up 22 per cent, allegations concerning individual officers or other staff represented 11 per cent, and discriminatory behaviour accounted for three per cent.
Police forces completed 107,616 complaints during 2025/26, 17 per cent more than in the preceding year.
Of those cases, 70,041 were dealt with informally.
A Thames Valley Police spokesperson said the force expects high standards from its personnel and treats every complaint with the utmost seriousness.
According to the spokesperson, performance on accessibility and the initial handling of complaints compares favourably with that of other forces.
The spokesperson acknowledged that further work was required in several areas, particularly the quality of investigations and ensuring that every person receives fair and respectful treatment.
The force would continue seeking improvements, while recognising shortcomings and taking corrective action to sustain public trust across its communities.
Thames Valley Police also explained that it uses a low threshold when accepting complaints so that concerns are correctly identified and resolved.
The approach is intended to ensure cases are understood properly, addressed thoroughly and handled transparently, supporting confidence in the force among local communities.
Matthew Barber, Police and Crime Commissioner for Thames Valley, said the force remained broadly in line with the national average when complaints were assessed against workforce size.
He attributed part of the rising volume to the policy of recording concerns at a low threshold and the growing use of artificial intelligence to submit complaints.
Barber’s office is continuing to review complaints data alongside Thames Valley Police to provide suitable scrutiny and accountability.
He also maintained that people with concerns arising from their experiences of policing should raise them, as feedback from the public contributes to service improvements and helps preserve confidence in the police.
IOPC Director of Oversight and Casework David Ford said the national figures should not be treated solely as evidence of increasing public dissatisfaction with policing.
He noted that the 15 per cent annual rise was the largest recorded year-on-year increase and that complaints had grown by 61 per cent since 2020-21.
The IOPC identified better recording practices by forces, more accessible complaint routes and greater use of artificial intelligence in complaint submissions as factors contributing to the increase.
The watchdog keeps in close contact with police forces to examine how their complaints systems operate, identify effective practices and share approaches that support timely, suitable case handling.
Public confidence in the ability to raise and have complaints considered remains central to the system.