Methods of accessioning, numbering, indexing and storage of the Tate Gallery Archive of Twentieth Century British Art are described. Material catered for includes: prints, drawings, posters, photographs, manuscripts, documents, press cuttings, microfiches and audiovisual material. Accessions are recorded on an IBM-PC using dBASE III software. Items are numbered in an annual sequence with a collection and piece number, and indexed via lists or cards. For some items, e.g., posters, a photographic copy is included in the index to minimize handling of original material. Storage units include acid free folders and mounts, archival solander and other boxes, plan chests, glass-fronted wooden cabinets, and custom made vertical storage units.