Systems and methods for supporting custom report layouts allow features that may be available to supported report layouts to also be made available to custom layouts. A custom layout definition may first meet a set of report definition criteria so that it is recognizable to report processing software. A design tool is provided that may be used to create such a custom layout definition. The custom layout may then be passed to report processing software. The report processing software can initially process the custom layout, and provide it with any features available in the initial processing stage. The reporting software may provide an interface for custom processing of the custom layout. The interface may be accessible to custom layout builder objects. Custom layout builder objects can be designed to use the report building components provided through the interface to build a custom report layout.