Custom fields & file upload

Collect exactly the information you need from B2B applicants by adding your own fields to the registration form — including file uploads that land directly in your Shopify Files.

Plan: Custom fields are available on the Advanced plan and above. On Free and Essential the built-in fields still work fully; only adding your own fields requires Advanced.

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Add a custom field

1. Open the form editor (Registration → Form settings → Edit form)
2. At the bottom of the Form fields list, click + Add element
3. Pick a field type
4. The field is added and selected — configure it in the right-hand panel
5. Save

On Free/Essential the + Add element button is replaced by an upgrade note.

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Field types & their settings

Type	Extra settings
Text / Textarea	Placeholder
Number	Minimum, Maximum, Step
Dropdown / Radio	List of options (add, remove, reorder)
Checkbox	— (a single consent tick)
Checkbox group	List of options (customer can tick several)
Date	Earliest date, Latest date
File upload	Allowed file types, Max size, Allow multiple

Every field also has Required, Width (full/half), Label, and Placeholder where relevant.

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How field IDs work

Each custom field gets a unique ID generated from its label:

• Chọn date → chon_date_a1b2
• Reseller license → reseller_license_9f30

Accents and special characters are stripped, spaces become underscores, and a short random suffix is added so two fields with the same label never collide — and a custom field never clashes with a built-in one. While the field is unsaved, the ID follows the label; once you save, the ID is frozen so existing submissions keep pointing to the right field even if you rename it.

Built-in fields keep their fixed IDs (firstName, email, …) and are never regenerated.

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File upload fields

A File upload field lets applicants attach documents such as a business license, tax certificate, or reseller permit.

Settings:

• Allowed file types — toggle PDF, Images (PNG/JPG/WebP), and Documents (DOC/DOCX)
• Max file size (MB) — 1 to 25 MB
• Allow multiple files — let the applicant attach more than one

What happens on submit:

1. When the applicant selects a file, the app uploads it immediately to your store's Shopify Files (Shopify admin → Content → Files)
2. The allowed types and size limit are enforced on the server, so they can't be bypassed from the browser
3. A link to each file is stored on the submission

Reviewing: in the submission detail, uploaded files appear as clickable links you can open or download while deciding whether to approve.

Files are stored in Shopify Files, not attached to the customer record. They remain available in your Files area for your reference.

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Where custom answers appear

Custom field answers are saved on the submission and shown in the submission detail when you review an application:

• File uploads → clickable links
• Checkbox group → the list of ticked choices
• Checkbox → Yes / No
• Everything else → the value as entered

They are kept on the submission for your reference and are not written onto the Shopify customer record.

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Languages

Custom field labels and placeholders can be translated per language, just like the built-in fields — switch the language tab in the editor and enter the translated text. (Dropdown/radio option labels currently display in your primary language.)