Add EIN Field to Shopify Registration (The Clear, Practical Guide for Merchants)

If you run a Shopify store that works with wholesalers, distributors, contractors, or B2B buyers, you already know how important it is to collect the right business information during signup. And one of the most common questions merchants ask is:

“How do I add an EIN field to my Shopify registration form?”

Or even more basic:

“Do I need an EIN for Shopify?”

“Where do I store a customer’s EIN number in Shopify?”

The truth is: Shopify doesn’t make this easy by default. Adding an EIN number field, validating it, and storing it correctly often requires custom Liquid coding, metafield setup, or manual work. And if you run a wholesale store, that becomes painful very quickly.

So in this guide, we’ll walk through — in simple language — why you need an EIN on Shopify, why defaults fall short, and the easiest way to add an EIN field to Shopify registration without coding, using Custlo.

Shopify is designed for general ecommerce, not B2B onboarding. When you try to add an EIN field to Shopify registration, you quickly run into three issues:

1. No Native EIN Field on Shopify Forms

Shopify does not include a built-in field for EIN. If you want to collect an EIN number on Shopify, you either need:

• Liquid coding
• Custom form scripts
• Theme edits
• Metafield mapping

This is why so many merchants search for: “how to add EIN to Shopify”, “Shopify EIN number field signup”, or “best Shopify app to collect EIN number.”

2. No Automatic EIN Storage or Validation

Even if you manually add an EIN number field through coding, Shopify doesn’t:

• Store the EIN in a structured place
• Map it to a customer metafield
• Validate the format
• Tag the customer as B2B or wholesale

So your team ends up doing this manually, which leads to mistakes and slows down wholesale approvals.

3. No Support for B2B Workflows

Most B2B merchants want to:

• Approve customers only if their EIN number is valid
• Tag customers automatically (e.g., “Reseller,” “Wholesale,” “Tax-Exempt”)
• Keep customer data synced across Shopify
• Trigger emails (e.g., “Your wholesale account has been approved”)

Shopify’s default registration form cannot do any of this.

After working with hundreds of B2B merchants, the requests are always similar:

• “I want to add an EIN field to the Shopify signup form without hiring a developer.”
• “I need EIN numbers stored properly in Shopify metafields.”
• “I want to approve B2B customers only if the EIN is correct.”
• “I want the registration form to feel professional and automated.”
• “I don’t want to mess with Liquid coding.”

This is exactly where Custlo solves the problem.

If you try to collect EIN without an app, here’s what the process actually looks like:

Step 1: Create a Custom Form Template

You must edit Liquid files, add new input fields, and manage error handling manually.

Step 2: Map the EIN Field to Shopify Metafields

You need to configure metafields like:
customer.metafields.business_details.ein_number

Step 3: Validate EIN Format Manually

You must check the structure manually or build your own validation script.

Step 4: Review & Approve Every Customer Manually

Your team has to check EINs one by one, then add tags and send emails.

Step 5: Maintain This Setup Forever

Every Shopify theme update breaks custom-coded forms.

Step 1: Install Custlo from the Shopify App Store

No coding. Just click install.

Step 2: Open “Custom Registration Form” Module

This is where you customize your Shopify signup form.

Step 3: Add EIN Field to Shopify Registration (Drag & Drop)

You simply drag the “EIN Number” field into your form.

• Input formatting
• Field validation
• Metafield storage
• Sync with customer records

Step 4: Add Additional Business Fields (Optional)

• Business name
• Reseller permit
• Tax ID
• EIN number
• Business type
• File uploads (certificates, documents)

Step 5: Set Approval Rules

• Auto-approve customers
• Manual approval after EIN review
• Tag customers based on EIN-type

Step 6: Publish Your Form

Your EIN-enabled Shopify registration form goes live instantly.

Custlo automatically maps the EIN number to a Shopify metafield, such as:
customer.metafields.custlo_b2b.ein_number

• You always know exactly where EIN data lives
• Other apps (Klaviyo, ERP, CRM) can read it
• Your team never has to search for missing EIN records

Feature	Default Shopify	With Custlo
EIN field on signup	Not available	Drag-and-drop
EIN validation	None	Automatic
EIN metafield mapping	Manual coding	Built-in
EIN approval workflow	Not available	Auto/manual review
B2B tagging	Not available	Automatic
File uploads	Not supported	Fully supported
Maintenance	High	Zero

• Faster B2B Approvals: Buyers can be approved instantly.
• Cleaner Customer Records: EIN stored properly in metafields.
• Less Manual Work: No spreadsheets or manual checks.
• More Trust & Professionalism: Feels like a real wholesale portal.

How many signups did you delay because EIN wasn’t collected correctly?

How much time does your team spend re-checking EIN numbers Shopify?

How many wholesale buyers dropped off because your form felt incomplete?

If any of these answers feel uncomfortable, you already know what needs to happen next.

Start your 14-day free trial of Custlo and add an EIN field to your Shopify registration form without a single line of code.

Your B2B onboarding could be live — and automated — in minutes.