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The Commonwealth Catalog (ComCat) extends your search beyond your local library’s resources. In one easy step, you can search through millions of items at participating libraries across Massachusetts to find the books, DVDs, and music you’re looking for. Make a request and it will be delivered right to your local library for quick pickup. You know what you want – let the Commonwealth Catalog help you get it. Click here to find out how.


Who do I contact if I have questions?
Contact your library with questions about using the Commonwealth Catalog.

How do I log into the Commonwealth Catalog?
You can login using a valid library card from a participating Massachusetts library network.  See the Login and My Account Guide for details.

How do I Request an item from the Commonwealth Catalog?
See the Searching and Requesting Guide for details.

How do I view My Request(s)?
Log into the Commonwealth Catalog. Click My Account at the top of the screen. In the My Account window under, My Transactions, click the link, ‘Items from other libraries’ to view a list of requested titles.

How long can I borrow the item?
Materials can be checked out for 28 days. Renewals are not allowed. Items should be returned at the library where they were picked up.

How many items can I borrow?
You can have 10 active requests on your account.  Requests marked as Complete or Passed to Local System are not included. If you exceed this limit you will receive an alert that your “ILL request limit has been reached.”  Return an item before placing a new request or contact your local library for assistance.

Can material be sent to my home?
Whether a book can be sent to your home or office is a local library policy and funding decision. Contact your local library to find out its policy.

I do not see my local library on the drop-down list to log in.
If you still do not see your library, please contact your local library for assistance.

I am unable to request the item I want.
Sometimes the Commonwealth Catalog does not allow you to request a title. This can be for a couple of different reasons.

  • “The item you have requested already exists in your local library” – The title is owned by and checked in on your local system. You will be directed to place a reserve the item on your local library system, and not through the Commonwealth Catalog.
  • All copies are not available (not on the shelf) or they are reference books and do not leave the library.
  • “ILL request limit has been reached” – You have exceeded 10 active requests.  You must return an item before placing another request.
  • You may be stopped if you have outstanding fines. Contact your home library to resolve the issue.
  • You are not properly logged in.
  • If the desired materials are not available through the Commonwealth Catalog, ask your local librarian about other interlibrary loan options.

How do I cancel a request?
Requests can be cancelled up until the time the item has been shipped by the lending library.

  1. When logged in, open the My Account window and click the link, ‘Items from other libraries.’
  2. In the grey title bar at the right of the request you wish to cancel click ‘Cancel this request.’ Once the Cancel request has been confirmed by the lending library, the request will be removed from your account. If you experience difficulty canceling your request, please contact your local library for assistance.

I have returned an item but the request is still on my Commonwealth Catalog account.
If the item has recently been returned to your home library, wait a few days for the library to process the return and check your account again. If it has been longer than a week, please contact your local library for assistance.

What if my items are overdue or lost?
If an item is lost or overdue you may be responsible for fines or fees.  Lost item replacement costs vary by the lending library.  Contact your local library to find out its policy.

I received an email notification regarding my request saying “Item Not Available” or “Unfillable.”
“Item Not Available” or “Unfillable,” means that the owning library (or libraries) is unable or unwilling to lend the item at this time. The owning library does not have to give a reason for denying the request. Some libraries have policies regarding lending of “new” items or multimedia items through the Commonwealth Catalog. If you still want the item, contact the staff at your home library. They may be able to assist you in borrowing the item. You can also try re-requesting the item at another time through the Commonwealth Catalog, though it is possible that the owning library may deny the request again.