How to Number Museum Objects
Updated October 23, 2026
A small museum should number objects using the year.accession.item format: the year the items were formally accepted, which numbered acceptance that was within the year, and which item within that acceptance. For example, 2026.3.1 means the first item of the third accession accepted in 2026. This is the standard registrar pattern because it ties every object permanently to the transaction that brought it in, and it never needs to be changed, reused, or guessed at again.
Why numbering this way matters
An object number is not a label for what the object is — it's a permanent pointer to how and when the museum acquired it. Two chairs can look identical, but if they arrived from different donors in different years, they need different numbers so their separate histories (who gave them, what restrictions apply, what condition they arrived in) never get confused.
Numbers are assigned once and never reused, even if an object is later deaccessioned. Reusing a number breaks the link between the physical object and its paper (or digital) trail forever, which is why professional registrars treat renumbering as something to avoid entirely.
The year.accession.item format, piece by piece
The first part of the number is the year the accession happened — not the year the object was made, and not the year it physically arrived if that differs from when the museum formally accepted it.
The second part is the accession number within that year: the 1st, 2nd, 3rd group of items formally accepted that year, counted in order. An accession is the formal acceptance of items from one source at one time — it's the moment ownership actually changes.
The third part is the item number within that accession: if a donor gives you five letters and a photograph in one gift, that's one accession with six items, numbered .1 through .6.
So 2026.3.1 reads as: the year 2026, the 3rd accession of that year, the 1st item within it. Every item in that same gift would share 2026.3 and differ only in the last number.
Where numbers come from in MuseumBuild
In MuseumBuild, objects cataloged from an accession get this industry three-part number automatically — you don't assign it by hand. The Collection menu follows the real registrar order: a Temporary Custody receipt holds items without transferring ownership, an Accession formally records acceptance (numbered by year, e.g. 2026-3 for the 3rd accession of 2026), and Objects cataloged from that accession inherit the year.accession.item number.
Objects created directly — legacy items already in the collection, or records brought in through import — may instead carry a prefix-year-NNNN pattern or whatever number was imported. Either way, the number is kept and never reused. Importing from a spreadsheet keeps your existing object numbers rather than reassigning new ones.
The normal path: custody, accession, then numbering
In practice, numbering follows a sequence, not a single step: someone brings items in and you write a Temporary Custody receipt, capturing the donor's story at the door while they're there to tell it. Later, you decide — accepting some items creates the formal accession (with its own checklist, the donor's restrictions, and the Deed of Gift), while declining or returning others needs no number at all.
Only accepted items get numbered. This is deliberate: a number should represent a real, owned object, not something still under discussion.
Adding an object with no new donor involved
Not everything comes through a new donation. If the museum already owns an object and there's no donor transaction to record, you can add it directly to the catalog. If you do know the source, creating an accession first is still the better practice — accession-linked records carry more history and are easier to account for later.
Common questions
What does 2026.3.1 actually mean?
It means the item is the 1st item cataloged from the 3rd accession formally accepted in 2026. Every other item from that same acceptance would share the 2026.3 prefix and differ only in the final number.
Can we reuse a number if an object is deaccessioned?
No. Object numbers are permanent and are never reused, even after a deaccession, so the historical record of what happened to that number always stays intact.
Do we have to assign the year.accession.item number ourselves?
No — when you catalog an object from an accession, MuseumBuild generates the year.accession.item number automatically as part of the normal accession-to-object flow.
What if an object was already in the collection before we started using MuseumBuild?
Objects created directly rather than from an accession — including legacy items and imports — can carry a prefix-year-NNNN pattern or keep whatever number they already had. Imports keep existing object numbers rather than replacing them.
Does every item in a single gift get its own number?
Yes. The accession number stays the same for everything accepted together, and each individual item gets its own final number — so a gift of six items becomes six numbers sharing one accession prefix.
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