A Shopify checkout tax ID field is a label you create, saved on the order before payment, and only if the checkout step can host an app block. SK Checkout Customizer lets you define extra fields and store the answers as cart or order attributes. The catalog does not include a field named Tax ID or VAT. You type that label. If the buyer is not checking out, and the sale is a quote, the ID belongs on the quote instead. SK Request a Quote stores a company tax ID and a VAT-exempt flag on the company record.
Those are two products. The checkout field rides along with a paid order. The quote field rides along with a company and a quote that can later become a draft order. Neither one files a return with a tax authority. Checkout-step placement is still a Plus question. Shopify’s help on checkout configurations documents app blocks on the information, shipping, and payment steps as Plus.
When you need the ID
The ID is late when it arrives by email after the order. Accounts then retypes it onto the invoice, and a mismatch becomes a credit note. If you invoice from the Shopify order, the number has to be on that order when it is created. A checkout attribute does that, on a plan that can place the field. EU and UK VAT numbers, and US tax IDs used by B2B buyers, are the same operational problem: the string must exist before the invoice is issued.
Ask for the ID only from buyers who should have one. A required VAT box on a retail checkout produces fake numbers. The checkout field can be required or optional. The validation function in the checkout app can also limit a cart rule to B2B or company buyers, which is a separate control from the text field. The catalog does not say the text field itself appears only for companies. If you need that targeting, test it in the editor. Do not assume a market rule the custom-field card does not document.
The Plus checkout field
Add a field, label it Tax ID or VAT number in the language your buyers use, and decide whether it is required. The answer is stored as a cart or order attribute. Your invoice template, or your finance team, still has to read that attribute. The catalog does not map the attribute into a tax exemption, a reverse-charge flag, or a government portal.
- Label: you name it. There is no built-in Tax ID switch.
- Storage: a cart or order attribute on the checkout order.
- Placement: the checkout step, which Shopify Help documents as Plus for app blocks.
- Price: the checkout app is free. Plus is the Shopify plan, not an app fee.
Checkout UI extensions need checkout extensibility. Confirm the field in the Plus editor, place a test order, and open the order in admin. If the attribute is missing, the invoice process is not ready. A thank-you field would be too late for an invoice you issue from the original order, and the catalog does not name the tax field as a thank-you block anyway.
The quote form, when the sale is not a checkout
Wholesale buyers who should not see a public price, or who need a negotiated total, are in a quote, not in a card form. The quote app’s company record can hold a tax ID, a VAT-exempt flag, a credit limit, and contacts. You assign quotes to that company. The checkout app does not write those company records, and the quote app does not write Shopify’s B2B catalogs. Company locations, market catalogs, and native Shopify companies are Shopify’s own B2B tools. Do not describe either Squadkin app as a replacement for them.
Converting an accepted quote can create a Shopify draft order, with discounts, shipping, tax, NET 7, 15, 30, 60, or 90 terms, and deposits, as the quote catalog documents. The tax ID on the company is still your reference data. It is not, by itself, a filed exemption. The quote app is also free, and it is a different install from the checkout app. The form builder app is a third product. Do not merge their feature lists.
Use the checkout field when a retail or B2B buyer pays immediately and finance needs the number on that order. Use the quote company when the commercial step is a quote. Some brands need both: a quote path for contract buyers and a Plus checkout field for smaller B2B orders that still pay by card. Test each path. Do not expect the tax ID to copy from the quote company onto a later checkout automatically. The catalog does not document that sync.
What neither path files
Storing a string does not validate the checksum of a VAT number, and it does not submit anything to a tax authority. If your finance process needs a format check, that check is outside both catalogs. A VAT-exempt flag on the quote company is a flag your team sets. It does not change Shopify’s tax calculation unless you configure taxes in Shopify yourself. Say that in the internal instructions so a new hire does not treat the field as a filing.
- Read the attribute on a test checkout order before you promise it to finance.
- Read the company tax ID on a test quote before you promise that path.
- Keep Shopify tax settings as the place rates are calculated.
- Keep government filing in the finance system that already does it.
Questions about tax ID fields
Is a checkout field the same as a tax exemption?
No. It stores the text the shopper typed. Exemption and tax rates stay in Shopify’s tax settings and in your finance process.
Can the quote app collect VAT without Plus checkout blocks?
Yes. The quote form and the company tax ID do not depend on placing an app block on the payment step. The sale has to be a quote, not a card checkout.
Will the field show in only one country?
The custom-field catalog does not document a per-market tax field. Test the editor before you promise that, and do not invent the rule.
Put the ID on a Plus checkout with SK Checkout Customizer, or on a quote company with SK Request a Quote, matching the way you actually sell. The checkout install is SK Checkout Customizer.