Correspondence

Letter to the Home Secretary on data access (accessible)

Published 25 June 2026

Migration Advisory Committee
2nd Floor Peel Building NE
2 Marsham Street
London
SW1P 4DF

enquiries@mac.gov.uk                                                                                   

June 2026

Rt Hon Shabana Mahmood MP
Home Secretary
2 Marsham Street
London
SW1P 4DF

Dear Home Secretary,

I write to you on behalf of the Migration Advisory Committee in regard to data access and quality. The Home Office’s ability to develop economically beneficial migration policies and our ability to provide you with robust analysis critically depends on high quality and timely data.

The Framework Document sets out that the Home Office as sponsoring department will provide access to the data required to carry out our duties effectively and assist in facilitating access to data held by other departments in a timely manner. Throughout our reviews over the years, we have highlighted persistent limitations in the availability, scope and usability of key datasets, which have and continue to constrain the robustness of our recommendations. We acknowledge that these improvements will take some investment to implement in order to develop the evidence base.

We recommend the following priorities:

Home Office

1. Ensure consistent use of application‑level identifiers across all visa routes. We welcome the ongoing development of application-level identifiers intended to link main applicants and dependants within a visa application. To be analytically useful however, this identifier needs to be implemented consistently across all visa routes and application channels, rather than applying only to a subset of applications. This will allow us to answer fundamental questions about household‑level outcomes, such as the characteristics of dependants accompanying Skilled Workers or the relationship between main applicants and sponsors in the Family route. Partial coverage would significantly limit its value for MAC analysis.

2. Record sponsor information consistently, including adding National Insurance numbers. In the Family route, the sponsor is typically a British citizen or resident. Their income, earnings history and household circumstances are central to evaluating the route, yet this information is neither captured nor stored in a usable format. Adding fields to routinely collect a sponsor’s National Insurance number (as recommended in our Family Route Review) would allow linkage to HMRC data and provide essential visibility on household income.

Cross‑government

3. Extend existing HMRC linkage with Home Office visa data to include DWP administrative data. We welcome the recent linkage between visa records and HMRC PAYE data and encourage the regular publication of analysis using this rich dataset. The most urgent next step is the linkage to DWP benefits data. This would allow us to answer basic questions about whether different visa groups claim benefits, at what rate, and with what fiscal impact.

Improving the timeliness, accessibility and quality of these data will enable us to strengthen our evidence base and provide policy recommendations that better serve the interests of the UK. We also believe that it will support others beyond the MAC in building the wider evidence on the impacts of migration.

On behalf of the Migration Advisory Committee,

Yours sincerely,

Dr Madeleine Sumption
Interim Chair, Migration Advisory Committee

cc:

Mike Tapp MP, Minister for Migration and Citizenship

Alex Norris MP, Minister for Border Security and Asylum

Gareth Davies, Permanent Secretary 

Simon Ridley, Second Permanent Secretary

Daniel Hobbs, Director General Migration and Borders