There are provided systems and methods for a payment information autofill mechanism that links a browser application with a user account such that a payment page at the browser application can be automatically filled based on the link. Specifically, the autofill mechanism establishes a link between a browser application running on a user device and a user account associated with the user that is stored at the server. When the user engages with the browser application to conduct a transaction on a merchant website, an application programming interface (API) call can be made to retrieve user virtual card information for automatically populating the payment data fields at the transaction page.