Skip to content
Vol. 1 · Ed. 2026
CyberGlossary
Entry № 009

Account Lockout

What is Account Lockout?

Account LockoutA control that temporarily or permanently blocks sign-in attempts after a configured number of consecutive failures, slowing online password-guessing attacks.


Account lockout disables an account after a threshold of failed authentication attempts is reached, raising the cost of online brute-force and password-spraying attacks. Active Directory, Entra ID, Okta, and most authentication platforms expose a triple: maximum attempts, observation window, and lockout duration (for example, 10 failures in 10 minutes leading to a 30-minute lockout). NIST SP 800-63B recommends rate limiting and intelligent throttling rather than aggressive lockouts because attackers can weaponize them to cause denial of service. Modern implementations therefore combine progressive delays, source-IP throttling, CAPTCHAs, and risk signals from systems like Microsoft Smart Lockout, which only locks the attacker's source while preserving legitimate logins.

Examples

  1. 01

    Microsoft Entra ID Smart Lockout that blocks the attacker's IP after 10 bad attempts while letting the real user sign in from another network.

  2. 02

    Banking portal that locks a card-holder's online access for 30 minutes after 5 wrong PINs.

Frequently asked questions

What is Account Lockout?

A control that temporarily or permanently blocks sign-in attempts after a configured number of consecutive failures, slowing online password-guessing attacks. It belongs to the Identity & Access category of cybersecurity.

What does Account Lockout mean?

A control that temporarily or permanently blocks sign-in attempts after a configured number of consecutive failures, slowing online password-guessing attacks.

How does Account Lockout work?

Account lockout disables an account after a threshold of failed authentication attempts is reached, raising the cost of online brute-force and password-spraying attacks. Active Directory, Entra ID, Okta, and most authentication platforms expose a triple: maximum attempts, observation window, and lockout duration (for example, 10 failures in 10 minutes leading to a 30-minute lockout). NIST SP 800-63B recommends rate limiting and intelligent throttling rather than aggressive lockouts because attackers can weaponize them to cause denial of service. Modern implementations therefore combine progressive delays, source-IP throttling, CAPTCHAs, and risk signals from systems like Microsoft Smart Lockout, which only locks the attacker's source while preserving legitimate logins.

How do you defend against Account Lockout?

Defences for Account Lockout typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for Account Lockout?

Common alternative names include: Lockout policy, Login lockout.

Related terms