Army key control regulations live primarily in two places: AR 190-11, which covers arms, ammunition, and explosives, and AR 190-51, which covers unclassified resources like offices, motor pools, and supply rooms. Together they require every unit to appoint key control personnel in writing, log every key transaction on DA Form 5513, inventory keys on a set schedule, store them in approved containers, and replace locks immediately when a key is lost. Break the chain and the consequences run from paying for the rekeying under AR 735-5 to non-judicial punishment or worse under UCMJ Article 92.
The Governing Regulations
AR 190-11 sets the standards for securing arms, ammunition, and explosives. It specifies lock requirements, the two-person rule for high-risk storage, and the inventory schedule for AA&E keys. AR 190-51 handles everything else on the installation that isn’t classified, from arms room adjacent office keys to motor pool padlocks. Installations layer their own supplemental regulations on top of these, so the local reg number in your key control binder may be different, but the core requirements trace back to the two Army-wide sources.
Who Has to Be Appointed, and How
A commander at battalion level or higher appoints a Key Control Officer in writing, and that appointment memorandum becomes part of the unit’s physical security plan.1U.S. Army. FLW Regulation 190-51 – Security of Unclassified Army Resources An alternate KCO must be appointed on orders as well. The KCO runs the program: maintaining the key control register, overseeing inventories, endorsing memorandums when locks are replaced, and checking that the custodians below them are doing their part.
Primary and alternate key custodians handle the actual issue and recovery of keys in their specific areas, whether that’s a platoon, motor pool, or supply room. Each custodian is appointed by memorandum and keeps a key control binder containing their own appointment orders, the KCO’s appointment orders, the current access roster, and all active DA Form 5513 registers.1U.S. Army. FLW Regulation 190-51 – Security of Unclassified Army Resources
If the locks and keys protect critical assets or controlled areas, the KCO should hold a security clearance at least equal to the classification of the material being protected. Anyone responsible for key control needs training covering lock compromise risks, lock maintenance basics, key security procedures, and the correct response when a key goes missing.2DTIC. Users Guide on Controlling Locks, Keys and Access Cards Personnel who maintain a master-key system need additional qualification, generally through a professional locksmith organization.
How Keys Have to Be Tracked
DA Form 5513
DA Form 5513, Key Control Register and Inventory, is the primary tracking document.3Department of the Army. DA Form 5513 – Key Control Register and Inventory Page one lists every key by number with the lock or area it opens. Page two logs every issue and return with date, time, printed name, and signature of both parties. Every transaction gets recorded in ink. No shorthand, no filling it in later.
Completed registers stay on file for at least one year after the last entry. When a new form is generated to reflect a change, the old form and any associated memorandums also stay in the file for at least a year.1U.S. Army. FLW Regulation 190-51 – Security of Unclassified Army Resources Inspectors check that retention timeline, and throwing out old registers early is one of the easier deficiencies to avoid.
The Two-Person Rule
For Category I storage facilities, meaning those holding the most sensitive items like certain missiles and night-vision systems, AR 190-11 makes the two-person rule mandatory. The lock system uses separate A and B locks, and no single individual is authorized for both keys.4U.S. Army. AR 190-11 – Physical Security of Arms, Ammunition, and Explosives Opening the facility always takes two people.
For arms storage below Category I, the two-person rule is at the commander’s discretion. Many commanders adopt it anyway because it produces a built-in witness to every opening. Where it’s used, the lock and key procedures have to be built so nobody can work around it.4U.S. Army. AR 190-11 – Physical Security of Arms, Ammunition, and Explosives
Inventory Schedules
Inventory frequency depends on what the key protects. Primary AA&E keys are jointly inventoried monthly by serial number, with the key custodian and armorer both present.5U.S. Army. FLW Regulation 190-11 – Physical Security of Arms, Ammunition and Explosives The secondary backup set has its container seal checked semi-annually by the KCO, key custodian, and armorer together.
For unclassified resource keys, the standard is a semi-annual inventory by serial number, with a written record kept until the next inventory is completed.6Kansas Adjutant General. AR 190-51 – Security of Unclassified Army Resources Electronic lock codes and pushbutton combinations also change at least semi-annually.
Category I munitions carry an extra safeguard. The monthly inventory must be conducted by a disinterested person, meaning someone not assigned to or directly responsible for the items. That person must be an NCO E-6 or above, a warrant officer, a commissioned officer, or a DoD civilian at GS-09 or above. The same individual cannot conduct the inventory in consecutive months.5U.S. Army. FLW Regulation 190-11 – Physical Security of Arms, Ammunition and Explosives
How Keys Have to Be Stored
Keys not in active use must be secured in a container that meets physical security standards. For keys to areas holding classified material or weapons, that means a GSA-approved security container, identifiable by the GSA approval or recertification label on the front.7U.S. General Services Administration. Security Containers For unclassified resource keys, a dedicated key depository with a manufacturer-installed tumbler lock is generally acceptable, though local regulations may raise the bar.
The container has to be physically anchored to the structure or sit inside a separately access-controlled space. The DA Form 5513 register is stored separately from the keys themselves. If someone can reach both at once, they can issue themselves a key and sign the log to cover it.
Sensitive lock systems use restricted keyways where blanks aren’t available on the open market. Only the manufacturer can cut additional keys, and only against a written authorization from the using activity bearing the proper signature.2DTIC. Users Guide on Controlling Locks, Keys and Access Cards Master and sub-master keys stay under the tightest possible controls, because a single lost master compromises every lock it opens.
Standard Form 702, the Security Container Check Sheet, records every opening, closing, and check of a security container by date, time, and initials.8National Archives and Records Administration. SF 702 – Security Container Check Sheet Combinations on vault doors and GSA-approved security containers used for arms storage change annually, whenever the custodian or armorer is replaced, whenever anyone with knowledge of the combination departs, or whenever compromise is suspected.9U.S. Army. JBLM Regulation 190-11 – Physical Security of Arms, Ammunition and Explosives The new combination is recorded on SF 700, sealed in the envelope provided, and stored in a container meeting AR 380-5 requirements. No other written record of the combination exists.
What Happens When a Key Is Lost
The clock starts the moment a key goes missing. The person who discovers the loss notifies the commander and the military police or security detachment immediately. A search follows, but for high-security areas the locks don’t wait for the search to finish.
The DoD standard for AA&E areas is that affected locks, cylinders, or cores must be replaced immediately when keys are lost, misplaced, or stolen.10Naval Facilities Engineering Systems Command. Users Guide on Controlling Locks, Keys and Access Cards The regulation says immediately, not within a grace period. In practice, the installation locksmith or DPW lock shop handles the physical rekeying, and the actual turnaround depends on workload and parts, but the expectation is that the unit initiates the work order the same day. For non-sensitive areas the rekeying timeline may be less urgent, but the lost key is still documented and the KCO endorses a memorandum for record explaining the circumstances and confirming lock replacement.
Between the loss and completed rekeying, the unit puts compensatory measures in place. That usually means posting a guard on the affected area or maintaining continuous surveillance until the locks are changed. A compromised arms room sitting unguarded while waiting on a locksmith is the scenario that generates real consequences for everyone in the chain.
Who Pays for the Rekeying
Rekeying costs money, and the Army decides who pays through the Financial Liability Investigation of Property Loss process under AR 735-5.11U.S. Army. Financial Liability Investigations of Property Loss Info Sheet
To hold a soldier or DA civilian financially liable, the approving authority must find three things: the person had a duty to care for the property, the person was negligent in carrying out that duty, and the negligence directly caused the loss. A Financial Liability Officer investigates and recommends a finding to the appointing authority. If all three elements are met, the individual can be charged for the cost of the new cylinders, cores, and labor.11U.S. Army. Financial Liability Investigations of Property Loss Info Sheet
The line between “lost” and “negligently lost” is where these cases turn. A key that falls off a ring during a field exercise and cannot be found after a thorough search may not clear the negligence threshold. A key left overnight on a desk in an unlocked office almost certainly does. The KCO’s memorandum for record and the work order for lock replacement become the foundational evidence in the FLIPL.
Disciplinary Exposure Under the UCMJ
Financial liability isn’t the ceiling. Key control failures can also carry disciplinary weight. The provision cited most often is UCMJ Article 92, which covers violating a lawful general order or regulation, failing to obey a known lawful order, and dereliction of duty.12Office of the Law Revision Counsel. 10 USC 892 – Art. 92 Failure to Obey Order or Regulation Key control procedures established by regulation or SOP sit squarely inside Article 92. A soldier who repeatedly fails to log key transactions or ignores inventory requirements is arguably derelict.
Most key control failures don’t reach a court-martial. The more common outcomes are non-judicial punishment under Article 15, a letter of reprimand, or an adverse counseling statement. For officers and senior NCOs, a letter of reprimand for a security violation can end a career on its own. Administrative sanctions can include a written warning, reprimand, suspension without pay, or removal from the position, depending on the severity and pattern of the conduct.
The exposure escalates sharply when a key control failure ends in the actual loss of a weapon or classified material. At that point the investigation shifts from administrative to criminal, and the consequences move well beyond paperwork.