The Disadvantages of Re-using Document Numbers
They are numerous reasons for not doing this as follows:
Typically, in most software applications, a document number is considered a Primary Key, so it should be considered “Unique” and would not be duplicated. However, there are some programs where it might be a Secondary key where multiples might be allowed, such as using a sequence Number, such as when using duplicate entries and historical tables such as Check History (e.g. checks, voids for the same checks, or manual payments, EFT transactions, etc.).
Even in situations where the programming might allow for this sort of thing, a duplication might cause other issues with software functionality, As examples.
- GAAP – According to GAAP (Generally Accepted Accounting Practice) document numbers should also be considered unique. This also makes auditing easier. If an auditor sees a lot of duplicate documents, it may prompt the auditor to dig deeper looking for other accounting irregularities, thereby artificially extending the length of the audit.
- The same Ticket/Invoice number exists in history multiple times – A user runs a report on ticket #20324 without having specified a date or date range. The subsequent report returns eight documents created over a period of 10 years.
- Problems posting – I have seen examples where end-users have used the same invoice number dozens of times. When they try to post a new voucher using the same invoice number, the program may hang or crash while it attempting multiple times to create a “New” document for one that already exists to previously. As an example, the program might attempt to write the same document into history 10 times, and then just stop the attempts to write the new data.
The worst example of this that I have seen so far, is with one vendor that 21 manual payments on file using an invoice and check number of “SUPPLIES” – In this case, a better example would create the numbers would be something like “SUPMMDDYY” (e.g. SUP031518).
If you have any questions or need assistance with the creating your own document number assignment schema, please contact the CCS Retail Systems Support department.