POP fiscal fields on cart for non-Plus Shopify stores

Configurationshopify2026-08-24

Goal

Add POP’s fiscal fields (customer type, VAT number, Tax Code, PEC/SDI) to the cart and/or cart drawer on a non-Plus Shopify store (Basic/Grow/Advanced), without a Checkout UI Extension.

Prerequisites

Non-Plus Shopify account.
Access to the theme code (theme.liquid or the cart section).

Steps

Paste the pop-noplus-embed.js script (provided by POP, loaded from pub.popapi.io) just before </body> in theme.liquid, or in the cart section/template, preceded by the window.POP_EMBED_CONFIG block with your parameters.

Full example configuration for an EU store (mode: 'peppol'), with custom text:

<script>
  window.POP_EMBED_CONFIG = {
    mode: 'peppol',
    scope: 'b2b+b2c',
    cartContainerSelector: '.cart__blocks',
    drawerContainers: [
      { selector: '.drawer__footer', insertMode: 'prepend' }
    ],
    insertMode: 'prepend',
    customerOptions: ['private', 'company'],
    toggle: { enabled: true, label: 'Add billing details' },
    labels: {
      title: 'Billing details',
      customerType: 'Customer type',
      private: 'Private',
      company: 'Business',
      vat: 'VAT number',
      vatPlaceholder: 'DE123456789'
    },
    prefill: {
      customerType: '{{ cart.attributes.pop_customer_type | default: customer.metafields.app.pop_customer_type | default: "private" | escape }}',
      vat: '{{ cart.attributes.pop_vat | default: customer.metafields.app.pop_vat | default: "" | escape }}'
    }
  };
</script>
<script defer src="https://pub.popapi.io/shopify/scripts/pop-noplus-embed.min.js"></script>

Save the theme.

Key config options: mode ('sdi' Italy — Tax Code required for private customers, validates PEC/SDI; 'peppol' EU — hides PEC/SDI, Tax Code not required; 'ksef' Poland — VAT/NIP; 'zugferd' Germany — hides PEC/SDI and Tax Code, VAT only for companies), scope ('b2b' forces “company”; 'b2b+b2c' shows the private/company/freelance selector), cartContainerSelector / drawerContainers / insertMode (where/how fields are inserted), toggle (show/hide a link to open the fields), prefill (initial values from cart.attributes, falling back to customer metafields customer.metafields.app.pop_*), and taxCodeOptOut (checkbox for sdi mode only, enabled by default — see below, its built-in default text is Italian-only).

Customizing text (`labels`)

Every visible label can be overridden via labels: {...} — omit a key to keep its default (in English, except toggle.label and taxCodeOptOut.label/note, whose built-in defaults are already in Italian):

Key	Default	Controls
`title`	”Electronic invoicing details”	Heading of the fields block
`customerType`	”Customer type”	Label of the customer-type select
`private` / `company` / `freelance`	”Private” / “Company” / “Freelance”	Customer-type select options
`vat`	”VAT number” (“VAT/NIP” in `ksef` mode)	VAT number field label
`taxCode`	”Tax code”	Tax Code field label (`sdi` mode only)
`pec`	”PEC or Recipient code”	PEC/SDI field label (`sdi` mode only)
`vatPlaceholder`	`IT12345678901` (`PL1234567890` in `ksef`, `DE123456789` in `zugferd`)	VAT field placeholder
`taxPlaceholder`	`RSSMRA80A01H501Z`	Tax Code field placeholder
`pecPlaceholder`	`you@pec.it / Z4G7P1Q`	PEC/SDI field placeholder
`errorVat`, `errorTax`, `errorRequiredVat`, `errorPec`	English validation messages	Per-field validation error text
`globalError`	”Complete billing details to proceed to checkout.”	Message shown when checkout is blocked for missing data

Alternative without an external script

If you’d rather have a self-contained form (inline HTML+CSS+JS, no external script from pub.popapi.io), ready-to-copy drop-in snippets are available, one per mode, in the public pop-snippets-library repository: cart-attributes-for-sdi.liquid, cart-attributes-for-peppol-b2b.liquid, and cart-attributes-for-peppol-b2b-b2c.liquid. They cover fewer cases (no dedicated zugferd/ksef support) but don’t require managing POP_EMBED_CONFIG.

Verify

Add a product to the cart.
Open the cart page (or the cart drawer, depending on where you inserted the containers).
Fill in the fields (e.g. VAT number).
Proceed to checkout.
Check that POP receives the data when the invoice is generated (see shopify-fiscal-data-management for where to verify it on the order).

Common errors

The fields don’t appear on a page — if the indicated CSS container (cartContainerSelector or drawerContainers) doesn’t exist on that page, the script simply shows nothing: it is not an error, check the selector.
Switching from “company” to “private” doesn’t clear the fields — this is expected behavior only if the change isn’t intercepted: in peppol/zugferd switching to “private” clears the VAT number, in sdi it also clears PEC/SDI, immediately syncing the cart attributes.
Shopify Plus stores — no need to modify the theme: use POP’s native Checkout Extension instead of the embed script.

On non-Plus stores, required/optional fields are configured here in the embed script (customerOptions, taxCodeOptOut), not in Settings > Checkout (that section applies to Shopify Plus only, see shopify-checkout-vat-tax-code-fields).