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Numeral calculates sales tax for your BigCommerce store in real time at checkout. You create a dedicated API account in BigCommerce, connect it to Numeral using those credentials, and Numeral takes over as your store’s tax provider — calculating tax on every order and syncing completed transactions, refunds, and voids back automatically. Before you begin, make sure you have:
  • Admin access to your BigCommerce store’s admin panel
  • A Numeral account
Numeral offers two ways to connect a BigCommerce store: through the BigCommerce Marketplace app (OAuth), or by connecting directly with API credentials. This guide walks through the API credentials method.

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Part 1: Create your API credentials in BigCommerce

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Step 1 — Create an API account

  1. In your BigCommerce Admin Panel, go to Settings → API → Store-level API accounts.
  2. Click Create API Account.
Create API Account

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Step 2 — Configure the API account

Configure API Account

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Step 3 — Select the required scopes

Set exactly these scopes — everything else should be left as None:
If any scope is missing, the connection may still be created, but some functionality will fail silently. For example, without Products: read-only, product sync won’t work.

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Step 4 — Save and copy your credentials

  1. Click Save.
  2. BigCommerce displays your credentials — copy both before closing the window:
Save credentials
Credentials are shown only once. If you close the window without copying them, you’ll need to delete this API account and create a new one.

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Part 2: Connect BigCommerce to Numeral

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Step 5 — Add a BigCommerce connection

  1. In the Numeral dashboard, go to Connections.
  2. Click Add Connection and select BigCommerce.
  3. Choose Connect with API credentials.
Connect with API credentials

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Step 6 — Enter your credentials and connect

Click Connect.
Numeral validates your credentials against BigCommerce, creates the connection, registers itself as your store’s Tax Provider, and starts syncing your product catalog — all automatically. This can take a few minutes to finish.

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Step 7 — Configure tax targeting in BigCommerce

Once connected, tell Numeral where it should calculate tax:
  1. In BigCommerce Admin, go to Settings → Tax.
  2. Next to Numeral, click Edit.
  3. Under Provider targeting, select the countries and subdivisions where Numeral should apply.
Tax targeting

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How it works

Once connected, Numeral acts as your BigCommerce store’s tax provider:
  1. A customer checks out in your BigCommerce store.
  2. BigCommerce calls Numeral to calculate tax for the order.
  3. Numeral returns the tax breakdown, which BigCommerce displays to the customer.
  4. When the order completes, Numeral commits the transaction for filing.
  5. Refunds and cancellations are automatically synced back to Numeral as adjustments or voids.

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Troubleshooting

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”Could not verify BigCommerce credentials”

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The connection was created, but tax isn’t calculating

  1. Confirm the Tax Provider registered successfully — check the connection status in your Numeral dashboard.
  2. In BigCommerce, go to Settings → Tax → Tax Services and confirm Numeral is enabled.
  3. Confirm the Information & settings: modify scope was selected when you created the API account.

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Need help?

Reach out to your Numeral implementation contact or email support@numeralhq.com.