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How to Set Up a Custom File Attachment Option in MultiVariants

Set up file attachments in MultiVariants with upload size limits, allowed file types, required uploads, add-on pricing, placement, and styling.

4 min read | Updated September 29, 2026

The File Attachment option in MultiVariants lets customers upload files when ordering a product. You can make the upload required, set a maximum file size, choose which file formats to accept, add an optional upload price, and display one shared upload field or a separate field for each variant.

Before You Start: Make sure the product is included in the ruleset where you want to add the File Attachment option. The upload field will appear on products that the ruleset applies to.

If you are new to Product Options, first see how to set up Product Options in MultiVariants.

How to Set Up a Custom File Attachment Option

Follow these steps to create and configure a File Attachment option.

Step#1 Open Product Options

>> Go to the MultiVariants dashboard and open an existing ruleset or create a new one. Then, open the Product Options tab and click + Add option.

MultiVariants Product Options tab with Add option button

Step#2 Select the File Attachment Option

>> Select File Attachment from the available option types and click Add option.

File Attachment option selected in MultiVariants Product Options

3. Configure the File Attachment Settings

>> Configure the fields based on how you want customers to upload files on the storefront.

  • Option title — enter the label customers will see above the upload field, such as “Upload your logo.”

  • Short description — add an optional short description to explain what customers should upload.

  • Help text — add optional instructions below the upload field, such as the maximum file size or accepted file formats.

  • Price — enter an optional additional charge that will be applied when the customer uploads a file. Leave it blank if the upload should not add an extra charge.

  • Max upload size (MB) — enter the maximum file size customers are allowed to upload. Files larger than this limit cannot be uploaded.

  • Required — set to Yes if customers must upload a file before adding the product to the cart.

  • Display on each variant — leave this unchecked to show one shared file upload field above the bulk-order section. Check it to display a separate upload field under each variant row so customers can attach a different file to individual variants.

File Attachment title, price, upload size, required, and per-variant settings

Step#4 Choose the Allowed File Types

>> In the File types section, select the file formats customers are allowed to upload.

  • Images — JPEG, PNG, WEBP, SVG, HEIC, GIF, TIFF, PSD

  • 3D models — GLB, USDZ

  • Documents — CSV, PDF, TXT, DOCX, XLSX

  • Archives — ZIP

  • Video — MP4, WEBM, MOV

  • Other — JSON

Supported File Attachment formats in MultiVariants

If no file types are selected, customers can upload any supported file format. Once you select specific file types, only those formats will be accepted.

Example: For a custom printed product, you could require customers to upload a PNG or PDF artwork file, set a maximum upload size, and add an optional charge for processing the custom design.

Step#5 Save the File Attachment Option

>> Click Save in the top save bar after reviewing the File Attachment settings.

Step#6 Test the File Attachment Option on Your Storefront

Open a product page where the ruleset applies and test the upload field. Confirm that supported files upload successfully, files outside your allowed size or format restrictions are handled correctly, required uploads are enforced, and any add-on price is applied as expected.

Manage File Attachment Placement and Styling

Add Another Product Option

>> Click + Add more options if you want to add another Product Option to the same ruleset.

Add more options button in MultiVariants Product Options

Choose the File Attachment Placement

Placement — determines whether the File Attachment option appears above or below the MultiVariants listing on the product page.

>> Click the gear icon at the top of the Product Options tab, select Above MultiVariants listing or Below MultiVariants listing, and click Save changes.

File Attachment placement above or below the MultiVariants listing

Customize the File Attachment Style

>> Click the gear icon at the top-right of the File Attachment option card to adjust the available styling settings, including border colors, background, text color, and border radius. Click Customize to apply the changes.

File Attachment styling settings in MultiVariants Product Options

Common Issues

The File Attachment option is not showing on the product page

Make sure the product is included in the ruleset where you created the File Attachment option and that the ruleset is active.

A customer cannot upload a file

Check the Max upload size and File types settings. Make sure the file meets the size limit and uses an allowed format.

Customers can add the product without uploading a file

Set Required to Yes if customers must attach a file before adding the product to the cart.

I need a different file for each variant

Enable Display on each variant to show a separate file upload field under each variant row.

The upload adds an unexpected extra charge

Check the Price field in the File Attachment settings. Remove or update the value if uploading a file should not add that charge.

Need Help?

If customers cannot upload files, the File Attachment option does not appear on the storefront, or your file size or format restrictions are not working as expected, contact the MultiVariants support team.

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