# I’m using the .NET Nuget AvaTax package to connect to AvaTax. Are account ID and license code enough for AvaTax API authentication?

Source: https://developer.avalara.com/products/ecm/integration-guides/document-management/ibl0095800851263/

Guide: Exemption Certificate Management (ECM)

# I’m using the .NET Nuget AvaTax package to connect to AvaTax. Are account ID and license code enough for AvaTax API authentication?

Learn whether account ID and license code are sufficient for AvaTax API authentication when using the .NET Nuget AvaTax package.

Yes, you can use either username/password or account ID/license code for authentication. However, if you're a technology partner, then you must also populate the [X-Avalara-Client http header](https://developer.avalara.com/avatax/client-headers/) with all your calls. Ensure the integration's (app name) element is set to this immutable value that identifies your integration.