You asked

I am looking to request UK crime statistics broken down by postcode.

We said

The Office for National Statistics (ONS) does not hold, or publish, police recorded crime data at the postcode level. The Home Office is responsible for police recorded crime data and they supply aggregated information to ONS to enable us to publish statistics for higher geographical areas, such as police force areas.

Monthly summary data relating to crime at street level (the most detailed geography available) is published by the Home Office via the www.police.uk website, and can be downloaded from https://data.police.uk/data/

Any queries regarding this data should be directed to the Home Office. Their contact email address is: crimeandpolicing@homeoffice.gsi.gov.uk