Methods and systems for authenticating communications sessions, such as voice and video calls, are described herein. A communications session, such as a video or voice call, may be detected. The communications session may relate to a transaction, such as a financial transaction. An authorization request may be received during the communications session. The authorization request may be received by a secure transaction application and via a first communications channel that is different from a second communications channel used for the communications session. A request to approve one or more goods or services to be purchased via the transaction may be displayed. In response to user input responding to the request, an authorization of the transaction may be transmitted to a server. The authorization may be configured to cause the server to initiate payment for the transaction using payment information associated with a user.