What is Data Matching?
Data matching involves comparing sets of data, such as the payroll or benefits records of a body, against other records held by the same or another body. This allows potentially fraudulent claims and payments to be identified. Where no match is found, the data matching process will have no material impact on those concerned. Where a match is found it indicates that there may be an inconsistency that requires further investigation.
Code of Data Matching Practice
The use of data for data matching purposes is governed by the C&AG’s Code of Data Matching Practice, the purpose of which is to help ensure that the C&AG, the Northern Ireland Audit Office, and all persons and bodies involved in data matching exercises comply with the law, especially the provisions of data protection legislation, and to promote good practice in data matching. The Code has been updated to take account of new data protection legislation, and has been consulted upon with the Information Commissioner and other key stakeholders. A copy of the revised Code and a summary of the key changes to the Code following consultation are at the links below:
Other Key Documents
- NFI Privacy Notice 2021 (PDF 506 KB)
- NFI Instructions 2020-21 (PDF 1.1 MB)
- NIAO NFI Self appraisal checklist (PDF 760 KB)
- Data Matching legislation - Article 4 of the Audit and Accountability (Northern Ireland) Order 2003 (PDF 244 KB)
NIAO's report on the most recent NFI exercise undertaken in Northern Ireland can be read at:
NIAO has also reported on the results of previous NFI exercises undertaken in Northern Ireland. These reports can be found on the publication section of our website.
For further Information, please contact the NIAO NFI Co-ordinator
Valerie Evans Tel: 028 9025 1062
Alternatively, you may send an email to:
To read more about NFI, follow this link to the UK Government website: