VuFind® supports two forms of interlibrary loan: ILS-based ILL and external service-based ILL.

When an ILS includes multiple locations, VuFind® includes Interlibrary Loan functionality in its ILS Driver API to allow support for user requests to move items from one location to another. As of release 2.3, this is only supported by the VoyagerRestful ILS driver, but can be added to any other driver for a system with the underlying capabilities.

As of release 5.0, VuFind® includes the option to use the Relais interlibrary borrowing platform for ILL requests. When an item is unavailable, VuFind® can be configured to search Relais for copies at other libraries and to allow users to place requests directly from within the VuFind® interface. To activate this feature, see the [Relais] section of config.ini.