There are provided systems and methods for dynamically linking machine-readable codes to digital accounts for loading of application data. A user may engage in a transaction with another user, such as a purchase of goods, services, or other items a merchant using a physical payment card. A machine-readable code may be provided on the payment card, where the machine-readable code may be dynamically linked to underlying data with an online transaction processor. The user may provide the payment card to another user that may capture the machine-readable code on the payment card. The other user's device may then utilize the machine-readable code with the online transaction processor to perform an account lookup using database information dynamically linked to the machine-readable code. Thereafter, the other user's device may automatically load account data for the account without having the user enter the account's identifier.