Honour-based abuse is a crime or incident committed to protect or defend the "honour" of a family or community. It can include forced marriage, domestic abuse, sexual violence, and threats to kill.
Home Office figures show 13 HBA-related offences were recorded by Devon and Cornwall Police in the year to March.
Across England and Wales, 2,755 HBA-related offences were recorded by the police last year, a fall of 8% from the year before and the first decrease since records began in 2020.
Of the offences last year, 111 were for female genital mutilation – up from 86 the year before. Forced marriage offences also rose from 173 offences in 2022-23 to 201 last year.
A spokesperson for Karma Nirvana, a charity for victims and survivors of the abuse, said: "The 8% decline in police-recorded HBA offences, despite a 13% rise in cases handled by Karma Nirvana's national Honour Based Abuse helpline, raises significant concerns.
"This drop may indicate ongoing challenges in accurately identifying, recording, and reporting HBA within police forces, rather than an actual decrease in HBA incidents."
They said the annual report on the offence "remains limited in scope" as it fails to capture "key details" such as the age of victims forced into marriage.
The charity urged the Government to improve data collection and called for the adoption of an honour based abuse statutory definition alongside training for frontline officers.
The Home Office said changes in May 2023 were made to the counting for conduct crimes such as stalking, harassment and coercive and controlling behaviour.
The requirement to record two crimes when one of them was a conduct crime was removed, which has led to a reduction in offences often associated with conduct crimes, such as malicious communications.
While this may have affected the level of HBA-related offences recorded in the last year, the Home Office said it is not clear that this change is the main driver for the fall in these offences.
A Home Office spokesperson said: "'Honour-based' abuse is a serious form of abuse that nobody should have to experience, which is why we are tackling it through our mission to halve violence against women and girls within a decade.
"The Government will use every tool at its disposal to bring perpetrators to justice and ensure victims receive the support they deserve."