The access versus holdings debate has been one of the 'hot topics' within the information world for some time, and the performance of document delivery services is an integral part of the discussion. This article focuses on work currently being undertaken at the University of Liverpool to investigate and evaluate existing and future document supply services. Reference is made to related literature, the background to the pilot projects is explained, and the criteria utilised for the inclusion of services are propounded. A detailed evaluation of the following services is included: BL's inside, BODOS, Ei Text from Elsevier Engineering Information Inc., LAMDA and UnCover. Preliminary results are reported. The conclusion to date is that, in their current form, document delivery services cannot be seen as a panacea for resolving the holdings versus access debate.