How It Works Compatible Features Pricing Contact
Guides Custom checkout fields PO numbers at checkout VAT numbers ABN at checkout Net terms & pay on account Capricorn members Repco trade accounts Burson trade accounts Checkout Blocks alternative Shopify native B2B alternative Security & data access
Install on Shopify
Custom Checkout Fields

Custom checkout fields for Shopify Plus,
the way that still works

The old way to add checkout fields — editing checkout.liquid — is gone. Today, custom checkout fields live in Checkout Extensibility. Trade Account Checkout adds validated business-reference fields to your Shopify Plus checkout: account numbers, PO numbers, VAT IDs — captured, validated, and saved as order metafields. No theme code.

Install on Shopify

Requires Shopify Plus · Free plan available

Quick answer

What are custom checkout fields on Shopify?

Custom checkout fields are extra inputs added to the Shopify checkout to collect information the standard checkout doesn't capture — a purchase order number, a VAT ID, a trade account or member number. On Shopify these are added with Checkout Extensibility (checkout UI extensions), which is a Shopify Plus capability; the old method of editing checkout.liquid has been deprecated. Trade Account Checkout is a checkout UI extension built for business references: it adds a configurable, regex-validated field to your checkout, saves the value to the order as a pinned metafield readable via the API, and auto-tags the order — all with no theme code, live in minutes. It is a field-capture extension, not a payment method.

The Short Version

One field can change how an order is handled

Shopify's checkout is deliberately lean — name, address, shipping, payment. That's right for most carts, but it leaves out the one detail a business buyer needs on the order: their reference. A contractor wants to quote a purchase order number. A wholesale buyer wants to put it on their trade account. A European B2B customer needs their VAT ID on the invoice. Without a field to capture it, that information arrives by phone, email, or order note — or not at all.

A custom checkout field closes that gap. The buyer enters the reference at checkout, it's validated against the format you expect, and it travels with the order into your admin and your systems. The difference between "we'll chase it later" and "it's already on the order" is one well-placed field.

What You Can Capture

Common custom checkout fields for B2B

Trade Account Checkout is purpose-built for business-reference fields. Each is configurable — your label, your validation, required or optional. Follow a link for the deep dive on each.

PO numbers

Capture, require, and validate purchase order numbers so every B2B order arrives with the PO already attached.

PO numbers at checkout

VAT / tax IDs

Collect format-validated VAT IDs from EU and UK B2B buyers, stored on the order for compliant invoicing.

VAT numbers at checkout

Trade & member numbers

Accept buying-group and co-op member numbers — Capricorn and any other — validated and pinned to the order.

Capricorn & buying groups

On-account references

The account reference behind net-terms ordering — paired with a manual payment method for pay-on-account.

Net terms & pay on account

Business identifiers

ABN, EIN, company registration or government procurement references — any business ID, with your own regex.

Fully configurable

Multiple fields at once

Need a member number and a PO on the same order? Add as many fields as you need, each with its own rules.

Your terminology
How They Work Now

Why custom fields now run on Checkout Extensibility

For years, Shopify Plus merchants added custom checkout fields by editing checkout.liquid or injecting Additional Scripts. That era is over. Shopify deprecated checkout.liquid in stages — information, shipping, and payment pages in 2024, then thank-you and order-status pages in 2025 — and has been auto-upgrading stores to Checkout Extensibility. Customizations that lived in checkout.liquid, including extra fields, stop working unless they're rebuilt as checkout UI extensions.

Checkout Extensibility is Shopify's modern framework: instead of editing checkout code directly, you add functionality through apps and UI extensions that run in a secure, upgrade-safe sandbox compatible with Shop Pay. Checkout UI extensions are a Shopify Plus capability — which is why a checkout-field app like this one requires Plus. The upside is real: no fragile code, no breakage on platform updates, and fields that are validated before the order is placed. The table below shows where each option stands today.

Way to add a field Status today Validated field inside checkout? Plan
checkout.liquid / Additional Scripts Deprecated — fully sunset and auto-upgraded No longer works —
Checkout Blocks custom fields Custom field collection removed No —
Cart note / line-item properties Works, but before checkout — not inside it Limited — not validated, not in-checkout Any
Checkout UI extension app Current and supported (e.g. Trade Account Checkout) Yes — validated, stored as order metafields Shopify Plus

Checkout UI extensions and Functions are exclusive to Shopify Plus. Some extensibility-powered apps offer limited customization on lower plans, but validated fields inside the checkout are a Plus capability.

At Checkout

Your field. Your label. Your rules.

An opt-in section sits with the contact details. The buyer ticks the box, enters their reference, and checks out through your existing payment setup — the value travels with the order.

In your checkout — alongside contact details
Your Store
Contact information
Contact buyer@company.com
I'm ordering on a business / trade account
Account number
TRADE-12345
PO number
PO-77821
Powered by TradeAccount
What Makes A Field Useful

A text box isn't enough

Capturing a value is the easy part. Capturing the right value, in a place your systems can use, is what makes a custom checkout field actually pay off.

Validation, not just a box

Enforce the format with a regex pattern and your own error message, so the value on the order is the value you expect — no typos, no junk.

Opt-in or required

Show the section only when a buyer opts in, or always-on. Make each field required or optional. Retail buyers never see what they don't need.

Stored as a metafield

The value lands as a pinned order metafield — visible to your team and readable via the Shopify API, so it flows into your ERP, accounting, or fulfilment.

Auto-tagged orders

Orders with a captured reference are tagged automatically — filter them in one click, export them, or trigger a Shopify Flow automation.

In Shopify Admin

Where the captured value ends up

Pinned to the order as a metafield, with the order auto-tagged — filterable, exportable, and ready for Shopify Flow. No separate dashboard to learn.

Order #1054 Payment pending
tag:trade-account
Tags — auto-applied at checkout
trade-account
Metafields — pinned, visible to your team
Trade account number
TRADE-12345
PO number
PO-77821
FAQ

Custom checkout fields — common questions

What merchants ask before adding a field to checkout.

What are custom checkout fields on Shopify?

Custom checkout fields are extra inputs added to the Shopify checkout to collect information the standard checkout doesn't — for example a purchase order number, a VAT ID, or a trade account number. On Shopify they're added with Checkout Extensibility (checkout UI extensions), and the captured value is saved to the order, typically as an order metafield.

Can I add custom fields to Shopify checkout without code?

Yes. With a checkout UI extension app like Trade Account Checkout you configure fields in the app's settings — label, placeholder, helper text, validation, and required-or-optional — with no theme code and no checkout.liquid. The old approach of editing checkout.liquid has been deprecated.

Do custom checkout fields require Shopify Plus?

Adding fields inside the checkout with a checkout UI extension is a Shopify Plus capability, so a checkout-field app like Trade Account Checkout requires Plus. Non-Plus stores can collect some information before checkout (such as cart notes or line-item properties), but those aren't validated fields inside the checkout itself.

How do I add a custom checkout field now that checkout.liquid is deprecated?

Shopify fully deprecated checkout.liquid — information, shipping, and payment pages in 2024, and thank-you and order-status pages in 2025 — and has been auto-upgrading stores to Checkout Extensibility. Custom fields that used to be injected via checkout.liquid now need to be rebuilt as checkout UI extensions, which is what Trade Account Checkout provides. See also the Checkout Blocks custom fields alternative.

Where are custom checkout field values stored?

Each captured value is stored as a pinned order metafield, visible to your team on the order in Shopify admin and readable via the Shopify API. Orders are also auto-tagged at checkout so you can filter, export, and trigger Shopify Flow automations.

Can I validate a custom checkout field?

Yes. Enforce any format with a custom regex pattern, show your own error message when input doesn't match, and add helper text to guide buyers. Validation runs before the order is placed, so the value on the order matches the format you expect.

Can I make a custom checkout field required or opt-in?

Yes. Each field can be required or optional, and the whole section can be opt-in — shown only when a buyer ticks a box such as "I'm ordering on a business / trade account" — or always-on. You can also add multiple fields, each with its own label and rules.

Is Trade Account Checkout a payment method?

No. It's a field-capture checkout extension, not a payment method or gateway. It does not capture, process, or charge payments. Customers complete checkout through your existing payment setup, and the app saves their reference to the order. Paired with a Shopify manual payment method, it supports a pay-on-account workflow.

Add the field your
B2B orders are missing

Install Trade Account Checkout and capture validated account numbers, POs, and VAT IDs at your Shopify Plus checkout — stored as metafields, auto-tagged, no theme code, no payment changes.

Install on Shopify