# What an Accession Number Records, and What It Does Not > An accession number dates a museum's custody, not the object. Five institutions in this archive use five incompatible formats, the number can contradict the credit line beside it, and a returned object loses its number altogether. > The Study - 2026-08-24 > Canonical HTML: https://iconotheca.com/study/what-an-accession-number-records/ ## Key points - An accession number dates a transfer of custody and nothing else. The Metropolitan Museum's Cristofori grand piano was built about 1720 and is numbered 89.4.1219a-c, accessioned in 1889; the Ardabil Carpet was finished in 1539-40 and is 272-1893, bought by the V and A in March 1893 for 2,000 pounds. - Five institutions in this archive use five incompatible grammars. The Met puts the year first, the V and A puts it last, the British Museum encodes the full registration date to the day, Cleveland uses year-point-sequence, and the Getty inserts a departmental letter code between the two. - The Met switched from a two-digit to a four-digit year prefix between 1969 and 1970, so 68.174 and 69.47.2 sort nowhere near 1970.301.3 in a list that a researcher reads as chronological. - The number and the credit line printed beside it routinely name different years. Three Benjamin Altman objects here are numbered 14.40.x with an accession year of 1914 under a credit line reading Bequest of Benjamin Altman, 1913, and the same one-year split recurs with the Walter C. Baker bequest at 1972.118.56. - A V and A number quoted without its department prefix is not unique: the museum's own search interface answers the string 272-1893 with four different objects, only one of which is the Ardabil Carpet. - A returned object loses its identifier. The Met's search index still answers a query for Nedjemankh with object 764111, that object record now returns 404, and the museum's own repatriation page lists the coffin by name with no number at all. ## An accession number dates the museum, not the object ## Five institutions, five incompatible grammars ## The number and the credit line beside it can name different years ## Without its prefix, the number is not unique ## When custody is unwound, the number is withdrawn ## How to cite a number so that it survives An accession number is the most trusted string in a catalogue entry and the least examined. It is an administrative claim, in a house format, about a transaction the institution itself conducted, and it can be revoked. Treat it as the strong dated evidence it is for the end of a provenance chain, and never as a fact about the object. ## Questions **Does an accession number tell me anything about when an object was made?** No. It records the year the holding institution took the object into its collection. The Metropolitan Museum's Cristofori grand piano of about 1720 is numbered 89.4.1219a-c because it was accessioned in 1889, and the Ardabil Carpet of 1539-40 is 272-1893 because the V and A bought it in 1893. **Why do the accession number and the credit line sometimes give different years?** The credit line dates the gift, bequest or purchase; the number dates the museum's own accession, which can fall in the following year. Three Benjamin Altman objects in this archive are numbered 14.40.x with an accession year of 1914 under a credit line reading 1913. For a provenance chain, the credit line year is the one that records when the previous owner parted with the object. **Is an accession number a permanent identifier?** No. It lasts as long as the museum's custody. The Met's number for the coffin of Nedjemankh no longer resolves after the coffin was returned to Egypt in 2019, and the museum's own list of restituted works names the object without a number. Kandinsky's Bild mit Haeusern lost its Stedelijk inventory number when it left that collection in 2022. **How do I check that a number I have found is the right one?** Put it into the holding institution's own catalogue and read the object that comes back against the object you mean. A number in the correct format for the correct museum can still belong to something else entirely, and nothing in the search result will warn you. Searching the V and A for the bare string 272-1893 returns four different objects. ## Sources - [1] Metropolitan Museum of Art, Open Access Collection API, object record 192708 (Cup, known as the Rospigliosi Cup), giving accessionNumber 14.40.667, accessionYear 1914 and creditLine Bequest of Benjamin Altman, 1913. - [2] Metropolitan Museum of Art, Open Access Collection API, object record 446648 (Dish, Iznik), giving accessionNumber 14.40.727, accessionYear 1914 and creditLine Bequest of Benjamin Altman, 1913. - [3] Metropolitan Museum of Art, Open Access Collection API, object record 501788 (Grand Piano, Bartolomeo Cristofori), giving accessionNumber 89.4.1219a-c, accessionYear 1889 and creditLine The Crosby Brown Collection of Musical Instruments, 1889. - [4] Metropolitan Museum of Art, Open Access Collection API, search endpoint queried for Nedjemankh, returning a single objectID, 764111, whose object record returns HTTP 404 while control records return HTTP 200. Checked 20 August 2026. - [5] Metropolitan Museum of Art, Repatriated Objects, the Museum's own page listing works it has restituted, which names the Coffin of Nedjemankh without an accession number. - [6] Victoria and Albert Museum, collection record for The Ardabil Carpet, museum number 272-1893. - [7] Victoria and Albert Museum, The Ardabil Carpet, museum article: The Museum acquired the carpet for 2,000 pounds in March 1893. - [8] Victoria and Albert Museum, collections search API queried for the string 272-1893, returning 272-1893 (The Ardabil Carpet), D.272-1893 (Album page), REPRO.1893-272 (Medal) and E.3:272-1893 (The Louvain Album). Checked 20 August 2026. - [9] Victoria and Albert Museum, collections search API queried for the string M.314-1962, returning a tea caddy by Paul de Lamerie, about 1730. Checked 20 August 2026. - [10] British Museum, collection record for the Sutton Hoo helmet, museum and registration number 1939,1010.93, acquisition name Donated by Mrs Edith M Pretty. - [11] British Museum, collection record for the Blacas ewer, museum and registration number 1866,1229.61, production date April 1232 (Rajab 629 AH). - [12] The Cleveland Museum of Art, collection record 1944.485, The Wade Cup with Animated Script, credit line Purchase from the J. H. Wade Fund, dated 1200-1221. - [13] J. Paul Getty Museum, collection record for Statue of a Victorious Youth, Object Number 77.AB.30, Department Antiquities. - [14] Metropolitan Museum of Art press release, The Metropolitan Museum of Art Returns Coffin to Egypt, 15 February 2019, on the July 2017 purchase of the coffin of Nedjemankh and the false ownership history the Museum received. - [15] Metropolitan Museum of Art press release, Metropolitan Museum Acquires Ancient Egyptian Gilded Coffin, 12 September 2017, whose image caption gives the full credit line ending in the accession number 2017.255b.