---
title: "Link Participants with supplemental identifier"
slug: "link-participants-when-both-guardiancaretakers-are-involved"
updated: 2026-05-17T11:39:05Z
published: 2026-05-17T11:39:05Z
canonical: "help.trialkit.com/link-participants-when-both-guardiancaretakers-are-involved"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.trialkit.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Link Participants with supplemental identifier

Some studies involve a primary Participant along with the Participant’s guardian or Care Partner. TrialKit can help you keep these linked. The primary purpose of this is to prevent user error where the study would normally otherwise require manual linking.

To assist with this linking, TrialKit provides a way to collect supplemental identifier on Subject registration forms. This identifier is something other than a subject ID that can help site users correctly identify each Participant. One example would be initials.

![](https://cdn.document360.io/7a6694f8-a35c-4fe3-abe9-1febe8020af7/Images/Documentation/image-US4OIT04.png)

Linked Participants are later reflected in the report builder and data exports. In other words if the Site users need a simple way to see which Participants are linked to a Care Partner, a readily-accessible list could be provided via the report builder.

[Read more here](/v1/docs/field-types-and-properties#key-identifier)