---
title: Prevent duplicate submissions
description: Allow only one completed response per person, per email address or per answer.
icon: copy-x
search:
  keywords: [duplicate, one response, unique, once per person, deduplicate]
---

Under **Settings → Responses → Prevent duplicate submissions**, choose:

| Option | How it works |
| --- | --- |
| **Allow multiple submissions** | Respondents can submit as many times as they like (the default). |
| **One response per answer** | Blocks a submission when a question's answer matches an earlier response. Pick an Email, Phone, Short answer, Number or Link question as the **Unique question**. |
| **One response per account** | Each signed-in respondent can submit once. Requires **Sign in to submit** under [Respondent identity](/settings/respondent-identity-and-sign-in). |

When someone tries again, they see _"You've already submitted this form."_ You can replace it with your own **Duplicate message**, or choose **Use the default message**.

:::note **One response per answer** checks the exact answer, so `ada@example.com` and `ada+1@example.com` count as different answers. For a strict one-per-person rule, use sign-in. :::