Understanding Labfront Participant Slots
This article explains what counts as a participant slot, how device sharing works, and why each participant needs their own account.
One slot equals one participant account
A participant slot corresponds to one Labfront participant account. Every unique person you enroll uses one slot, regardless of which device they collect data on.
Reusing a device doesn't reduce slot usage
You can reuse the same Garmin device across multiple participants. Slot limits track participant accounts, not devices. For example, if 10 people use the same device at different points in your study, that's 10 participant slots, not one.
Learn more about sharing a device between participants→
Completing a participant doesn't free up their slot
Participant slots are one-time use. Once a participant activates and starts their one-year data collection window, their slot is consumed, whether or not they finish the full year.
Marking a participant "Completed" closes their profile. It doesn't release or refund their slot for reuse.
For example, if you've used 34 of your 50 slots, marking those 34 participants "Completed" still leaves you with 34 used and 16 available, not 50 available again.
Learn more about participant completion→
Why each participant needs their own slot
You need to set up a separate slot for every participant, even when they share a device, because reusing one slot across multiple people overwrites or mixes their data. Once that happens, you can't reliably attribute the data to one person, which makes it unusable for analysis.
Learn more best practices for Labfront studies→
FAQ
Does reusing a device for a new participant use up another slot?
Yes. Slots track participant accounts, not devices. A new participant, even on a device you've used before, needs their own slot.
Can I reassign a participant's slot to someone else once they finish the study?
No. Once a participant activates, their slot is consumed for good. Marking them "Completed" closes their profile but doesn't free the slot for a new participant.
Why can't two participants share one Labfront account?
Sharing an account mixes both participants' data into a single record. There's no reliable way to separate it back out afterward, which makes it unusable for analysis.
How many slots do I have, and what happens if I run out?
Basic and Advanced plans include 20 participant slots. You can see how many slots you have used and how many are remaining on your dashboard. Need more? Contact us to add more slots to your workspace.