---
title: "File Upload Restrictions"
description: "Restrict what a File Upload field accepts, from allowed file types by curated groups to a maximum size per file, so requests arrive with the documents you expect and nothing you don't."
category: "Building workflows"
updated: 2026-08-27
canonical: https://approvethis.com/docs/manuals/file-upload-restrictions
---

# File Upload Restrictions

A File Upload field accepts anything by default, which is how a 400 MB video or a stray .exe ends up attached to a purchase request. On the Files tab of a File Upload or Multiple File Upload field card, you tick the curated type groups the field should accept — Documents, Images, Spreadsheets, Archives — and set a per-file size cap in megabytes. Both are enforced on the form when a requester attaches a file, so bad uploads never reach an approver. You'll need a published or draft workflow whose form already contains a File Upload field; this guide picks up on that field's card.

**Who this is for:** an Administrator.

> **Prerequisite:** Sign in as an Administrator.

> **Getting here:** A File Upload field is configured from the workflow's Form tab: expand the field's card and open its Files tab.

## Restrict the field to the file types you accept

An invoice field that quietly accepts screenshots and zip archives creates work for whoever opens the request. Ticking the groups you actually accept narrows the field to those extensions at upload time. One caution: custom extensions outside the built-in 31-extension MIME map are silently dropped from enforcement — paired with mapped types, files of that unmapped extension get rejected anyway, and configured on their own, no type restriction applies at all and every upload is accepted.

1. Sign in as an Administrator and open the workflow's Form tab.
2. Click **Attachments** to open the File Upload field's card.

   ![Click Attachments to open the File Upload field's card.](https://approvethis.com/docs-assets/manuals/file-upload-restrictions/screenshots/file-upload-restrictions-s1-01.png)

3. Click **Files** to switch to the field's file restriction settings.

   ![Click Files to switch to the field's file restriction settings.](https://approvethis.com/docs-assets/manuals/file-upload-restrictions/screenshots/file-upload-restrictions-s1-02.png)

4. Click **Documents** to accept document file types.

   ![Click Documents to accept document file types.](https://approvethis.com/docs-assets/manuals/file-upload-restrictions/screenshots/file-upload-restrictions-s1-03.png)

5. Click **Images** to also accept image file types.

   ![Click Images to also accept image file types.](https://approvethis.com/docs-assets/manuals/file-upload-restrictions/screenshots/file-upload-restrictions-s1-04.png)


> **Success cue:** The accepted-extension list updates as you tick each group, ending with image formats such as **.webp**.

## Cap the size of each uploaded file

Large attachments slow down approvers on a phone and eat storage for no benefit. A per-file cap in megabytes stops the oversized file on the form rather than after it lands on the request.

1. Enter the per-file size limit in megabytes in **Maximum File Size** — the example uses `10`.

   ![Enter the per-file size limit in megabytes in Maximum File Size — the example uses 10.](https://approvethis.com/docs-assets/manuals/file-upload-restrictions/screenshots/file-upload-restrictions-s2-01.png)

2. Press `Tab` to commit the value.

   ![Press Tab to commit the value.](https://approvethis.com/docs-assets/manuals/file-upload-restrictions/screenshots/file-upload-restrictions-s2-02.png)


> **Success cue:** The value you typed stays in **Maximum File Size** once the field loses focus, confirming the cap is saved.

> **What happens next:** How the two limits are enforced: when a requester attaches a file, the form rejects anything larger than the size cap, and anything whose extension is not on the accepted list. The size the field records is in megabytes.