This article gives you an overview of the keyboard shortcuts that are supported in Bill Pay.
1 2 3 4 5 (after you click a document):
Switch between the tabs on an open document (Details, Activity, Payment, Integrations and Chat, respectively).
A / D (after you click a document):
Approve or decline the open document.
⬆ / ⬇ or J / K (when a document is open in fullscreen view):
Go back to the previous document or on to the next document in the list.
E / Esc :
Open a document in fullscreen view after you click it, or close fullscreen view.