GST HST Number Lookup Canada 2026

Here's the thing: that GST number on your supplier's invoice? If it's wrong, inactive, or fake, the CRA will deny your Input Tax Credit claim faster than you can say "audit." And in 2026, with the feds cracking down on GST/HST compliance, you simply can't afford to wing it anymore.

Why GST Number Verification Matters More Than Ever

Let me be blunt: the CRA doesn't care if your supplier gave you a "valid-looking" number. If they're not registered on the exact date of your transaction, you're on the hook for the full tax amount with no credit. In 2026, with e-invoicing requirements expanding, Revenue Canada's systems are getting smarter at catching mismatches.

Every time you claim an Input Tax Credit (ITC) from an invoice with an invalid GST number, you're essentially throwing money away. The CRA can claw back those credits years later, plus interest and penalties. That "small oversight" could cost you thousands.

What You Need Before You Start

Here's where most folks go wrong — they jump into the registry without gathering the right intel first. The CRA's system is precise, and if you're off by even one character, you'll get a "not found" result that tells you nothing.

• GST/HST account number: Grab the first 9 digits only (ignore the letters). Full format looks like 123456789RT0001 — but you just need the numbers before "RT"
• Exact legal business name: Not the trade name or DBA. The exact name registered with the CRA. When in doubt, ask your supplier for their official registration documents
• Transaction date: The specific date on the invoice. Registration status can change overnight, so precision matters. A business might be active today but wasn't on the date you paid

Step-by-Step: Using the CRA GST/HST Registry

The CRA's registry isn't fancy, but it gets the job done. Here's exactly how to use it without pulling your hair out:

Step 1: Head to the official CRA GST/HST Registry page (search "CRA GST/HST Registry" — it's the first result)

Step 2: Enter the 9-digit business number. Pro tip: double-check you haven't included any letters or spaces

Step 3: Input the exact legal business name. If you're not 100% sure, try variations or call the supplier. This is where most searches fail

Step 4: Select the transaction date from the calendar picker

Step 5: Hit search and pray to the tax gods. If it says "registered" — you're golden. If not, you've got a problem

Step 6: Crucial: Print or save a PDF of that confirmation screen. The CRA won't accept "but I checked it" as proof. You need the screenshot with a timestamp

The Registry's Limitations (Yes, It Has Flaws)

Now for the honest truth — the CRA's tool isn't perfect. Understanding its quirks will save you false confidence and potential headaches.

Name matching issues: The registry only checks the first 10 characters of the business name. So "Acme Supplies Ltd" and "Acme Super Supplies Ltd" could both validate with the same number. Always verify the full name on official documents.

Update delays: When a business registers or cancels, there's often a lag before the registry reflects the change. If you get a "not registered" result for a new supplier, follow up directly.

No financial details: The registry won't tell you if they've filed returns or remitted taxes. It only confirms registration status on a specific date. A registered business could still be non-compliant.

Provincial variations: Quebec's QST system is separate. For QST numbers, you need Revenu Québec's verification tool. Don't mix these up — the CRA registry won't help with Quebec suppliers.

Red Flags That Scream "Verify This NOW!"

Certain situations should set off alarm bells. If any of these sound familiar, drop everything and verify:

• New supplier with suspiciously low prices (they might not be planning to remit GST)
• Invoice shows a GST number but the business name looks slightly off
• Supplier is reluctant to provide their GST number or registration proof
• You're dealing with a vendor who recently changed ownership or structure
• The invoice is over $100 and doesn't show a GST number (legally required)
• Your tax planning calculations show unusually high ITCs from one supplier

When the Registry Fails: Your Backup Plan

Sometimes the registry gives you grief even when the number is legit. Don't panic — you've got options.

Call the CRA Business Enquiries line: 1-800-959-5525. Have the GST number, business name, and transaction date ready. The agent can confirm registration over the phone and provide a reference number for your records.

Ask for registration documents: Legitimate businesses can provide their GST/HST registration confirmation letter from the CRA. This is ironclad proof.

Use your tax professional: If you're dealing with complex multi-province situations, a professional can verify through CRA agent channels not available to the public.