Accession Number Calculations

Updated 13 October 2026 12:38

Accession Numbers consist of a Number Sequence and a Prefix. The Number Sequence is a number of a specified length that counts up as new specimens are added. The Prefix consists of the other togglable elements.

Year
Month
Specimen Type
Free Text

Note: For more information on custom accession numbers, see: LINK TO CUSTOM ACCESSION NUMBER ARTICLE.

The calculation refers to what aspects of the prefix reset the number sequence to zero. For elements that change under certain criteria (Year, Month, Specimen Type) it can be useful to include or exclude these from the calculation. For example, when Specimen Type is enabled and included in the calculation, each unique specimen type mapping will have its own number sequence that will increment independently of each other.

bl0000000000001
cf0000000000001
bl0000000000002
bl0000000000003
cf0000000000002

If the Specimen Type is enabled but excluded from the calculation, then the number sequence will be shared between each of the Specimen Types. An example of this may look like this:

bl0000000000001
cf0000000000002
bl0000000000003
st0000000000004
cf0000000000005

In this scenario, the changing Specimen type does not reset the number sequence. All togglable elements of the Accession Number can be included / excluded from the calculation.

Note: Accession Numbers must be unique so if a scenario arises where Prefixes overlap, the system will increment accordingly. For example: if Specimen Type mappings are set such that 2 or more have the same code, each will increment using a shared Number Sequence.

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