# Frequently Asked Questions
>Last modified: 20 Jan 2026

<div style="background-color: rgba(0, 178, 169, 0.3); padding: 10px; border-radius: 5px;"><strong>FAQs based on enquiries received by researchers working in the UK LLC Trusted Research Environment.</strong></div style>  
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This section is aimed primarily at researchers. It provides links to the FAQs for each section of Guidebook. More FAQs will be added as more datasets become available in the TRE.

Please follow the links below for FAQs on:

- [Longitudinal Population Study (LPS) data](../lps_data/lps_faq.md)

- [NHS England data](../linked_health_data/nhs_england/nhse_faq.md)

  - [Hospital (HES) datasets](../linked_health_data/nhs_england/hes_datasets/hes_faq.md)  
  - [COVID-19 datasets](../linked_health_data/nhs_england/covid_datasets/covid19_faq.md)  
  - [Mental health datasets](../linked_health_data/nhs_england/mental_health_datasets/mh_faq.md)
  - [Medical codes (e.g. ICD-10, OPCS-4, SNOMED)](../linked_health_data/nhs_england/coding/codes_faq.md)

- [Place-based data](../linked_geo_data/place_faq.md)

- [Administrative data](../linked_admin_data/admin_faq.md)

- [UK LLC-managed data](../ukllc_managed_data/ukllc_managed_faq.md)

- [Working in the TRE](../user_guide/tre_faq.md) 

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>If the answer to your question is not covered in these FAQs, please email the UK LLC Data Team at [**support@ukllc.ac.uk**](mailto:support@ukllc.ac.uk)