## Documentation Index Access the complete documentation index at: https://www.zoho.com/in/books/kb/llms.txt Use this file to discover all available documentation pages before proceeding. [Back](./) # Why am I not able to associate tax in the bill for an unregistered vendor? If the Vendor is unregistered under GST Preference, then tax can be associated on the basis of Reverse Charge. First, we need to configure the tax preference of the organisation by enabling reverse charge for Sales transactions. Here’s how: * Go to **Settings** in the top-right corner. * Click **Taxes** under _Taxes & Compliance_. * Click **GST Settings** from the left menu. * Mark the **Enable Reverse Charge in Sales transactions** checkbox under _Reverse Charge_. Here’s how you can enable the reverse charge option and associate tax: * Go to _Purchases_ from the left sidebar and click **Bills**. * Click **+New** under _Bills_. * Select the **This transaction is applicable for reverse charge** checkbox and enter the required details. * Click **Save**. * * *