Verify Customer GSTINs on the Cart Page

Collecting a GST number on the cart page is only half the job. A mistyped or cancelled GSTIN means a B2B invoice your customer cannot claim credit on, and a correction request for you later. GST Pro can now check the GSTIN a customer types against the official GST registry, show them the registered legal name, and refuse cancelled or suspended numbers, all before the order is placed.

Prerequisite: the Collect Customer GST app embed must already be enabled on your cart page. See How to Collect Customer/B2B GST Number in Cart page.

What the customer sees

With verification on, the GST details card on your cart page gets a Verify button next to the GST Number field.

1. The customer types their 15-character GSTIN. The field uppercases it automatically and checks the format as soon as they leave the field.

2. They click Verify. GST Pro looks the number up in the GST registry.

3. A dialog titled Verified with the GST registry shows the legal name, GSTIN, registration status, and where available the trade name, registration type, registered on date and address.

4. The customer clicks Save GSTIN. A green Verified tick and the legal name appear under the field, and the details are attached to the cart.

If you also collect the company name, GST Pro fills the Company Name field with the registered legal name when the customer left it blank. Anything the customer already typed is never overwritten.

Editing the GSTIN after saving clears the verified status immediately, so a stale "verified" flag can never reach checkout, including through accelerated checkouts such as Shop Pay.

Cancelled or suspended GSTINs

If the registry returns a GSTIN that is not active, the dialog changes to Found in the GST registry and explains:

This GSTIN is cancelled in the GST registry, so it can't be saved for GST invoicing.

The Save GSTIN button is hidden. The customer can close the dialog and still complete checkout as a regular B2C order. Verification never blocks checkout.

Messages the customer may see

Turning verification on

1. In GST Pro, go to Customers and click Collect GST Number.

2. In the Cart page card, make sure Shopify cart (Online Store) is selected and the app embed is enabled. If it is not, click Enable App Embed and turn on Collect Customer GST in your theme editor.

3. Switch on Verify GSTINs against the GST registry.

4. Click Save in the bar at the top of the page.

The Verify button appears on your cart page immediately. Turning the switch off removes it again without touching your theme.

Styling the Verify button

The look of the button and dialog is controlled from the theme editor, under the Collect Customer GST app embed settings, in the GSTIN verification group:

• Verify button label (default "Verify")

• Verified accent color, used for the tick, badge and active status

• Verify button background and Verify button text color

• Verification corner style: None, Soft or Round

Whether verification is on or off is decided only in the GST Pro admin. The theme settings change appearance only.

Where the verified details go

Verified details are saved as cart attributes and arrive on the order as note attributes:

• gstin_number: the GSTIN

• company_name: the company name, when that field is enabled

• gstin_verified: true after a successful verify and save

• gstin_legal_name: the legal name from the registry

GST Pro reads these when it generates the invoice, so the B2B invoice carries the verified GSTIN and legal name without any manual edits.

Plans and limits

• Verification is available on the Business plan and above. Collecting a GSTIN without verification works on every plan that includes the Collect GSTN feature.

• Lookups go against a shared GST registry connection, so GST Pro applies fair-use limits: a handful of live lookups per minute per store and a daily cap per store and per shopper. Repeat lookups of the same GSTIN are served from cache for seven days and do not count.

• When a limit is hit or the registry is down, the customer sees "Couldn't verify right now — you can still continue" and can save the GSTIN unverified or proceed without it.

Good to know

• Verification is available only on the Shopify cart page through the app embed. The product page block, the checkout fields and the Custom cart implementation snippet collect the GSTIN without a Verify button.

• The registry's state and address are shown to the customer but are not compared against the shipping or billing address.

• There is no per-store verification log in the admin. The verified flag and legal name are visible on each order's note attributes.