Guidance for submitting a cohort submission file

A guide to submit participant data securely through NHS England’s Secure Electronic File Transfer (SEFT) platform

Before you start

We recommend reading each guidance section in full, including the pre-submission checklist before you submit your cohort submission file.

Throughout the guidance, you will see reference to the word cohort. A cohort is a group of individuals with shared characteristics, for example, age or location. Specifically for this service, a cohort refers to a list of participants who have consented to data sharing.

Introduction

An overview of the Participant Validation Engine (PaVE) and how Secure Electronic File Transfer (SEFT) and Master Person Service (MPS) are used to deliver submissions.

Preparing your submission

Instructions on prerequisites, how to use the cohort template and guidance on which identifiers to include to maximise trace success.

Pre-submission checklist

Before submitting your cohort file, check you can answer yes to the questions in the pre-submission checklist.

Submitting your cohort

Details of account and folder requirements for the cohort submitter, file size limits and minimisation information.

Managing your cohort

How to update and manage your cohort.

Outputs and results

Description of the outputs you will receive after you make your submission.

Contact us

If you have read through the guidance and require further support, raise a support ticket with our National Service Desk who will pass your query to the correct team to contact you.

Last edited: 26 January 2026 9:59 am