A system for acquiring tax data during electronic tax return preparation includes a client computer configured to render a first webpage and receive interface data from a tax data source computer. The system also includes a browser server computer configured to receive the interface data from the client computer, process the interface data to generate rendering instructions, and transmit the rendering instructions to the client computer. The client computer and the browser server computer are configured such that, when the client computer executes the rendering instructions, the client computer renders a secondary webpage. The secondary webpage is controllable independent of the primary webpage.