Can Google Forms cap the number of people per time slot?

Native Google Forms cannot cap per-option selections. You need an add-on that removes or closes options when a quota is reached, or a Apps Script solution.

How do I keep the slot list in sync with my schedule?

Keep the slots in a Google Sheets column and sync them to the form question. With FormSuite Choice Sync you can run Preflight, update once, and check the public preview before sharing.

What happens when all slots are full?

With a response limiter such as FormGuard, the form can close automatically and show a custom message. You can also schedule a reopen for a later registration window.

Time slot sign-ups

Google Forms time slot sign-up with limits

Parent-teacher conferences, lab sessions, appointment days, volunteer shifts — they all need the same thing: one question with time slots, each slot capped at a fixed number of people, and the form closing when everything is full. Google Forms alone can't do the per-slot cap. This page shows the practical setups, from manual to no-code.

Install Choice Sync (dynamic slots) Install FormGuard (slot caps)

Quick answer

Keep your time slots in one Google Sheets column, sync that column to a multiple-choice question, and cap each slot with a choice quota. When every slot is full, a response limiter closes the form with a custom message.

Your three options compared

Manual removal

Free, but you (or a volunteer) must watch responses, edit the form, and delete full slots by hand — including at night and on weekends.

Apps Script

Full control if you maintain code: an onFormSubmit trigger can decrement counts and rewrite choices. Realistically you become the maintainer of that script.

Add-on combo (no code)

Choice Sync keeps the slot list synced from your Sheet; FormGuard caps each slot and closes the form when done. Both free to install and test.

The no-code setup, step by step

Create your Google Form with one multiple-choice question named "Time slot".
List every slot as an option (e.g. "Thu 3:00 PM", "Thu 3:20 PM", "Thu 3:40 PM").
Install FormGuard from the add-on store, open its sidebar, enable Choice quota, and set a cap per slot (e.g. 8 people per slot).
When a slot fills, FormGuard removes it from the choices automatically.
Optional: enable the response limit and a custom "all slots are full" message for when the whole form should close.
If your schedule changes, edit the slots in the Sheet and use Choice Sync to push the new list to the form — run Preflight, update once, and check the public preview.

Test before sharing. Submit 2-3 test responses yourself (or from an incognito window), confirm the quota removes the right slot, and only then share the form link.

FAQ

Can respondents see remaining slots?

Google Forms shows the options that still exist. When a slot's quota is reached and the option is removed, later respondents simply no longer see it.

Can I reopen a slot?

Yes — re-add the option (manually or via Choice Sync) and it becomes selectable again. You can also reset quotas in the FormGuard sidebar.

Does this work for appointments across several days?

Yes. Group slots by day in the Sheet and sync the full list; use section navigation in Forms if you want days split across pages.

What if two people grab the last seat at once?

Forms processes submissions sequentially, so the quota removes the option after the first submission is recorded. For absolute certainty, verify the final count in the response Sheet.

Ready to set it up?

Both add-ons install free and run their full first-run test before you share anything with respondents.

Choice Sync — dynamic slots FormGuard — slot caps & limits