How is Interlibrary Loan (ILL) different from Prospector?

Both ILL and Prospector are used to fill requests for physical materials that CU Boulder doesn’t have. While Prospector only locates materials within select libraries in Colorado and Wyoming, ILL locates and fills requests for materials held worldwide.

Due to the proximity of and speedy delivery from Prospector libraries, it’s always best to search for an item in Prospector prior to using ILL. If ILL staff identify that an item requested is available at a Prospector library, they will fulfill the request through Prospector.

What can I request?

You can request books, DVDs, CDs, dissertations, microforms and other materials held by lenders worldwide. In addition to physical materials you can also request scans of articles and book chapters. ILL staff are able to fulfill the vast majority of materials requested no matter the format. 

Can I request an e-book?

Not at this time. e-books are covered by special publisher licensing that doesn’t allow this format to be borrowed by other libraries. 

Do my requests have to be for research materials?

ILL should be used to support your academic and research purposes. If you wish to request materials for personal use, please try Prospector or your local public library first. All requests for non-research related materials will be accepted at the discretion of the ILL staff.

Can I request textbooks?

If the textbook is required for one of your classes, it is best not to request it through ILL. The Libraries are not able to fulfill most requests for textbooks because they are often not widely available to be borrowed from libraries.

Who can use ILL?
  • Currently enrolled degree seeking students at CU-Boulder
  • Currently enrolled degree-seeking Continuing Education students
  • Currently employed faculty and staff
Who can’t use ILL?
  • CU Boulder Law students, faculty and staff -- ILL is available by contacting the CU Boulder Law Library 
  • Non-degree Continuing Education students
  • Public patrons
  • Faculty/Staff spouses not affiliated with CU Boulder
  • Institute workshop participants
  • Other CU campus students and faculty (UCCS, UCHS & UCD)
  • Friends of the Libraries (Silver, Gold and Platinum)
  • Senior auditors
How do I request materials?

To make a request, log on to ILLiad and enter your IdentiKey username and password. Once logged on, place a new request by first choosing the format type (book, media, article, thesis, etc.). Fill out the request form with as much information as possible. The more information provided, the greater the likelihood it will be filled quickly. A lack of information may necessitate cancelling the request.

Do I have to sign up for ILLiad using my email?

Yes. To ensure that our emails get to you, we need to use your email for all communications. 

Does ILL cost me anything?

ILL is free to CU-Boulder students and employees. The cost for borrowing materials, as well as shipping, is paid for by the Library. We would ask you to please remember this and request materials that you truly need for your research.

How can I check on the status of my request?

Log on to your ILLiad account and you’ll be able to view all the requests that you have made. Requests that have not yet arrived or are in processing will appear on the main page. Materials that have arrived or are currently checked out are listed in “Checked out Items”. To view any article or book chapter request that you’ve had filled within the last 30 days, click on the “Articles Received” link.

Why is my ILLiad account blocked?

If your account is blocked, you may have overdue items or be a patron type that doesn’t receive ILL privileges. Please contact the ILL staff at for more information. 

Why haven’t I received my ILL yet?

Some requests are harder to fill than others. If an item requested is new and popular, it may take several weeks to find a lender with a copy available. If the item requested is difficult to find, it may take time to locate a lender. Processing and shipping may also be time consuming. Some libraries, such as Library of Congress, require 20 working days to process a request. 

What happens if my ILL materials are overdue?

If you have materials that are two weeks overdue, your ILLiad and Chinook accounts will be blocked. At 28 days overdue, you’ll be billed a lost item fee of $400 plus a billing fee of $10.

What happens if I return my ILL materials after I have been billed the lost book fee?

If your materials are returned prior to the library paying the lender’s invoice for the replacement cost, the $400 replacement fee will be waived. The $10 billing fee will remain. Billing fees will only be waived as a courtesy only once.

I lost or damaged my ILL material. Can I replace it?

Please contact us before purchasing a replacement:

Interlibrary Loan (ILL) Borrowing



I am not a CU-Boulder student or employee, but I would like to borrow something from the library. How can I do that?

If you’re a local resident, please contact the Norlin Circulation Desk about public patron privileges. If you’re not a local resident and you wish to borrow an item through ILL, please contact your local library about their ILL policies and place a request through them. While the University Libraries do lend out the majority of their collections, these materials are lent only to other institutions and not to individuals.