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Perpetual Access (PA): What is Perpetual Access (PA)?

This guide provides information on what Perpetual Access is, and how it is being utilized at USC Libraries for Collection Management.

What is Perpetual Access?

Perpetual access (PA) relates to titles in collections and packages that USC Libraries' subscribe to from vendors where it has been previously agreed upon that USC Libraries will retain permanent e-based access on those titles if and when the subscription has stopped. Additionally, titles within collections and packages that USC Libraries' purchase outright have PA.


A couple questions related to PA:

  • Can the library lose access to old issues?
    • Vendors has been providing me lists with perpetual access date ranges for titles that include a start-year (a number of titles have start-years during the mid-1990s, like 1995-1996). For end-year of perpetual access ranges, an end-year could be the year when the journal title ended its publication, the last year a vendor carried a title before it moved to another vendor for distribution, or for active journal subscriptions and packages, perpetual access is maintained until the subscription/package is canceled and the date of cancelation would be the end-year.
    • i.e. if a journal subscription is canceled in December 2019, USC would be provided e-access to issues from the applicable start-year until last issue in December 2019.
    • For issues before a vendor’s perpetual access start-year (like before 1995-1996), there are times vendors offer these older issues within e-accessible collections that are either known as backfiles or archives that can be purchased at one time with complete ownership. USC Libraries does have a number of backfile and archives collections that were previously purchased, and those are collections noted within Primo/Alma.
  • Can a subscription to a particular journal end?
    • As mentioned previously, for titles where there is an active subscription/package, the library will have perpetual access to e-based issues until a time when it is decided to cancel the subscription, if the journal ends its publication, or perhaps if the journal moves to another vendor for distribution.


Vendors and publishers may use other terminology for "perpetual access" in regards to the collections and materials available for purchase and/or subscription.

Terms in Contracts and/or Agreements

  • Post-cancellation access
  • Continual access
  • Moving wall OR Embargo

Terms Found in Package/Collection Names

  • Archive
  • Archives
  • Backfile
  • Backfiles

What DOESN'T have Perpetual Access?

At this time, the following electronic collections and packages with the following terms in the the title are considered NOT to have perpetual access:

  • Open
  • Open Source
  • Free