What is the difference between event-based retention and time-based retention, and how do you set up each one?

Retention periods tell you how long a record must be kept before it can be destroyed or transferred. The key difference between the two main approaches is what starts the clock: a fixed calendar interval, or a triggering event.

Time-Based Retention

Time-based (or fixed-period) retention sets a defined length of time measured from a known starting point, such as the date a record is created, received, or filed. Once that period elapses, the record becomes eligible for its disposition action.

Examples in plain terms include keeping certain financial or tax records for a set number of years after the filing date, or retaining routine correspondence for a fixed term after creation.

This approach is the simplest to administer because the cutoff and destruction dates can be calculated automatically from the creation date.

Event-Based Retention

Event-based retention does not begin counting until a specific business event occurs. The retention “trigger” is the event; a fixed period often follows it.

Common triggers include:

• Contract expiration or termination
• Employee separation
• Closure of a case, matter, or project
• Disposal of an asset or product end-of-life

A rule might read “retain for X years after the contract ends.” Until the event is recorded, the record stays in an open, indefinite state.

Setting Up Each One

The setup process shares a common foundation: identify the record series, determine the legal, regulatory, and business requirements, and document the rule in an approved retention and disposition schedule.

For time-based rules:

• Define the start (creation, receipt, or fiscal-year cutoff)
• Set the duration and the disposition action
• Let the system calculate eligibility automatically

For event-based rules:

• Define the qualifying event precisely so it can be recognized consistently
• Establish how and where the event date is captured (a status field, a workflow, or a manual update)
• Apply any follow-on time period that runs from the event

The hardest part of event-based retention is reliably capturing the trigger. Records can sit in limbo if no one records that the event happened, so build the trigger into a process or system rather than relying on memory.

In practice, many schedules combine both: an event starts the clock, and a fixed period follows. Whichever you use, the rule should be approved, documented, and applied consistently across the records it governs.