Account linking is is where you link your voice app to an existing user account or device. For example link the voice app to your smart lights, or link the voice app to an existing web account.

The benefit of account linking in a voice app expands the function of your app which can lead to increased functionality, personalisation of the experience or bring in third party data.

A example could be you have an existing account with an eCommerce website. Linking your account to an Alexa skill / Google action made by the same eCommerce website could then enable you to check the status of orders via your smart speaker rather than logging onto the website.

Account linking should be a one time process for the user.