First, head to your Account Settings.

Next, ensure your BN is set to show on your Quote and Invoices.

Then, add or edit your BN.

When you're ready, click 'Save'.

Your BN will now be listed on your Quotes and Invoices.

You can also add your Tax ID to the end of a Tax Type name (e.g., HST #1225366585). This will appear in the 'Total' section at the bottom of your client-facing material.