Defense contractors began to see PIIDs in the Delivery Order field of contracts in early 2017.   This change was driven by an amendment to Federal Acquisition Regulation (FAR) 4.16 that required the revised numbering system to ensure uniformity and consistency of data across Federal agencies. 

This abrupt change had significant impact on Mil-Std-129R labeling, which for decades had identified contracts by a thirteen-character Contract Number and a four-character Delivery Order Number.   Increasing the latter by nine characters impacted label formats, machine-readable data specifications and the downstream systems utilizing these labels.   The result was Change Notice 1 to Mil-Std-129 Revision R, under which the PIID was substituted for the combination of the Contract and Order Numbers.

The impact of the PIID to Wide Area Workflow (WAWF) was negligible because it has always defined its Delivery Order field to be sufficiently large to accommodate the PIID.   However, contractor systems that defined Delivery Order in terms of the four-character SPIIN did have to make accommodations for the longer data.


Prior to adoption of the PIID, defense shipments were identified by:

  • PIIN – Procurement Instrument Identification Number, aka Contract Number, and sometimes…
  • SPIIN – Supplemental PIIN, aka Order Number

Requisitions made against a contract are more common with purchase orders issued by the Defense Logistics Agency (DLA). They are not referenced on Mil-Std-129 labels and have a somewhat secondary role in WAWF.  It might be tempting to combine PIIIN and Requisition Number to uniquely identify a procurement instrument, but that would be entirely unwieldy and blow up data management systems left and right. The PIID solves this problem and gives visibility to DLA purchase orders in WAWF.  

Use of the PIID solves the problem of uniquely identifying delivery orders (which are independent contractual documents) and requisitions, as well as contracts that utilize neither. This while fitting neatly within the traditional data space definition of a PIIN.   The definition of PIID by Mil-Std-129 makes the use of PIIDs more clear.

5.1.2.f. Procurement Instrument Identifier (PIID) (e.g. contract number or purchase order number). The PIID shall be shown. When applicable, use the 13-digit PIID call order number (identified by F or M in the 9th position) alone (since the call order is treated as an independent contractual document). For legacy contracts, cite the PIIN including delivery order or call number if applicable shall be shown. (see 5.1.1f).   

[Mil-Std-129R, Change Notice 1]

Recognizing a PIID

The presence of a PIID is obvious in contracts with a Delivery Order that is 13-17 characters long.  It is less obvious in looking at Mil-Std-129 labels on which the PIID is substituted for Contract Number.  The key is that position nine (after removing any dashes) which will be an ‘F’ or ‘M’.  

Do I Keep Using PIIN?

That is up to you.   The PIID may be used in place of the contract number on WAWF transactions. However, the Government recognized that contractor systems might want to be able to easily relate all documents and actions on contracts that are delivered through multiple delivery orders or requisitions.  WAWF supports that desire by continuing to allow a contract number and PIID when the later is expressed as the delivery order number. It will treat delivery orders as PIIDs when they are of 13-17 characters with ‘F’ in position 9.

It is possible to substitute PIID for the contract number in systems that only create Mil-Std-129 labels.  However, doing that will cause a loss of visibility of the contract number.  Ideally, the labeling system will automatically substitute PIID for the contract number on labels, allowing shipments to be identified by both internally.   However, for systems that submit labeling data to WAWF in Receiving Reports, Invoices and RFID updates, maintaining both the contract and PIID has advantages.