# AC-9 — Previous Logon Notification

- **Control ID:** AC-9
- **Family:** [AC](/md/families/AC.md)
- **Baselines:** No content available.
- **Enhancement of:** No content available.

## Description

Notify the user, upon successful logon to the system, of the date and time of the last logon.

## Discussion

Previous logon notification is applicable to system access via human user interfaces and access to systems that occurs in other types of architectures. Information about the last successful logon allows the user to recognize if the date and time provided is not consistent with the user’s last access.

## Implementation guidance

No content available.

## CSF 2.0 subcategories

- [DE.CM-09](/md/csf/DE.CM-09.md) — DE.CM-09

## Related controls

- [AC-7](/md/controls/AC-7.md)
- [PL-4](/md/controls/PL-4.md)

---

Derived from official NIST publications (NIST SP 800-53 Rev 5 and NIST CSF 2.0). nistcontrols.com is not affiliated with NIST.