Number sequences overview
Dynamics 365 for Finance and Operations has evolved into purpose-built applications to help you manage specific business functions. For more information about these changes, see Dynamics 365 Licensing Guide.
Number sequences are used to generate readable, unique identifiers for master data records and transaction records that require identifiers. A master data record or transaction record that requires an identifier is referred to as a reference.
Before you can create new records for a reference, you must set up a number sequence and associate it with the reference. We recommend that you use the pages in Organization administration to set up number sequences. If module-specific settings are required, you can use the parameters page in a module to specify number sequences for the references in that module. For example, in Accounts receivable and Accounts payable, you can set up number sequence groups to allocate specific number sequences to specific customers or vendors.
When you set up a number sequence, you must specify a scope, which defines which organization uses the number sequence. The scope can be Shared, Company, Legal entity, or Operating unit. Legal entity and Company scopes can be combined with Fiscal calendar period to create even more specific number sequences.
Number sequence formats consist of segments. Number sequences with a scope other than Shared can contain segments that correspond to the scope. For example, a number sequence with a scope of Legal entity can contain a legal entity segment. By including a scope segment in the number sequence format, you can identify the scope of a particular record by looking at its number.
In addition to segments that correspond to scopes, number sequence formats can contain Constant and Alphanumeric segments. A Constant segment contains a set of letters, numbers, or symbols that does not change. An Alphanumeric segment contains a set of letters or numbers that increment every time that a number is used. Use a number sign (#) to represent incrementing numbers and an ampersand (&) to represent incrementing letters. For example, the format #####_2017 creates the sequence 00001_2017, 00002_2017, and so on.
Number sequence examples
The following examples show how to use segments to create number sequence formats. In particular, the examples demonstrate the effects of using scope segments.
Expense report numbers
In the following example, expense report numbers are set up for the legal entity that is titled CS.
- Area: Travel and expense
- Reference: Expense report number
- Scope: Legal entity
- Legal entity: CS
|Segment 1||Legal entity||CS|
Example of formatted number: CS-EXPENSE-0039
You can set up a similar number sequence format for other legal entities. For example, for a legal entity that is named RW, if you change only the value of the legal entity segment, the formatted number is RW-EXPENSE-0039. You can also change the whole number sequence format for other legal entities. For example, you can omit the legal entity scope segment to create a formatted number such as Exp-0001.
Sales order numbers
In the following example, sales order numbers are set up for the company ID CEU.
- Area: Sales
- Reference: Sales order
- Scope: Company
- Company: CEU
Example of formatted number: SO-0029
Even though a scope segment is not included in the format, numbering restarts for each company ID. If you use the same format for all company IDs, the same numbers are used in each company. For example, sales order number SO-0029 is used in each company. You can also change the whole number sequence format for other company IDs.
Purchase requisition numbers
In the following example, purchase requisition numbers are organization-wide.
- Area: Purchase
- Reference: Purchase requisition
- Scope: Shared
Example of formatted number: Req0052
Because the scope is Shared, the number sequence format is used across the organization. You cannot set up different number sequence formats for different parts of the organization.
Performance considerations for number sequences
Consider the following information about how the configuration of number sequences can affect system performance before you set up number sequences.
Continuous and non-continuous number sequences
Number sequences can be continuous or non-continuous. A continuous number sequence does not skip any numbers, but numbers may not be used sequentially. Numbers from a non-continuous number sequence are used sequentially, but the number sequence may skip numbers. For example, if a user cancels a transaction, a number is generated, but not used. In a continuous number sequence, that number is recycled later. In a non-continuous number sequence, the number is not used.
Continuous number sequences are typically required for external documents, such as purchase orders, sales orders, and invoices. However, continuous number sequences can adversely affect system response times because the system must request a number from the database every time that a new document or record is created.
If you use a non-continuous number sequence, you can enable Preallocation on the Performance FastTab of the Number sequences page. When you specify a quantity of numbers to preallocate, the system selects those numbers and stores them in memory. New numbers are requested from the database only after the preallocated quantity has been used.
Unless there is a regulatory requirement that you use continuous number sequences, we recommend that you use non-continuous number sequences for better performance.
Automatic cleanup of number sequences
In case of a power failure, an application error, or other unexpected failure, the system cannot recycle numbers automatically for continuous number sequences. You can run the cleanup process manually or automatically to recover the lost numbers.
Carefully consider server usage when you plan the cleanup process. We recommend that you perform the cleanup as a batch job during non-peak hours.