Defense Travel System SSN Justification Memo

OFFICE OF THE SECRETARY OF DEFENSE
1950 DEFENSE PENTAGON
WASHINGTON, DC 20301-1950

ADMINISTRATION AND
MANAGEMENT

February 1, 2021
Ref: SSNJ-2021-0010-DHRA
MEMORANDUM FOR THE DEFENSE TRAVEL MANAGEMENT OFFICE
SUBJECT: Justification for the Use of Social Security Numbers in the Defense Travel System
(DTS) - Accepted
Thank you for completing a review of Social Security Number (SSN) use within this
system. The Defense Privacy, Civil Liberties, and Transparency Division (DPCLTD) has
reviewed and accepted your request to use the SSN for the following Acceptable Use: (4)
Interactions with Financial Institutions. The Defense Travel Management Office (DTMO) is
required to provide the SSN to the government travel card provider (Citi) for verification
purposes.
The DPCLTD has also reviewed and accepted your request to use the SSN for the
following Acceptable Use: (7) Federal Taxpayer Identification Number. In cases of
investigations and audits, the SSN is required to allow law enforcement and tax authorities to
cross-reference and validate account numbers and user identifications in the system.
The DPCLTD has also reviewed and accepted your request to use the SSN for the
following Acceptable Use: (8) Computer Matching. The DTS exchanges data with more than
twenty systems through the Global Exchange Service interface, which sends and receives all
DTS financial transactions to Department of Defense (DoD) financial systems for computer
matching purposes. The SSN is the primary identifier for most of these systems and is required
to facilitate obligation or payment.
The DPCLTD has also reviewed and accepted your request to use the SSN for the
following Acceptable Use: (11) Legacy System Interface. The database receives records from
each of the Service’s personnel systems. Currently, none of the Service personnel systems have
transitioned to the use of the DoD Identification Number, although DTMO has encouraged such
change. The only way to uniquely identify using the above named data source is to request and
use the SSN.
SSN use by the system is approved indefinitely until a reasonable alternative for
identifying individual records is established or the DTS is decommissioned.
While this system has been identified as requiring the collection, maintenance and use of
the SSN, you must ensure this data is afforded the highest protections practicable through use of
appropriate administrative, technical and physical safeguards. Also, please maintain a copy of
your justification and this memo in your records. The reference number for this approval is
listed at the top of this memorandum.

If you have any questions, please contact Ms. Viki Halabuk in this office at
viki.l.halabuk.civ@mail.mil.
KIRBY.LYN.M
.1590283483

Digitally signed by
KIRBY.LYN.M.1590283483
Date: 2021.02.01 09:57:49
-05'00'

Lyn M. Kirby
Chief, Defense Privacy, Civil Liberties,
and Transparency Division
cc:
DHRA Privacy Office
DMDC Privacy Office