Update 2019: This post is updated with screenshots based on SharePoint 2019.

Update 2016: This post was initially written in June 2008. The User Information List still exists in SharePoint 2016 and onward.

Note: This list is only visible to and accessible by administrators.

Updated quick links for common troubleshooting:

User Information List – Background

In SharePoint, we have the User Information List in SharePoint, which stores information about users. Some examples are Picture, Email, DisplayName, LoginName, and more.

For a complete list of fields, see further down this blog post under "User Information List Fields".

Something to note is that when a user gets access to a site, a new item will be created in the User Information List, storing some information about the user.

When a user adds/create or edit an item, SharePoint will display something like "Last modified at 1/1/2008 by Tobias Zimmergren" like the following pic:

Hidden User Information List modified and created metadata information by SharePoint system.

In this example the DisplayName (used to display System Account) is gathered from the User Information List.

Browsing the User Information List

The User Information List can be accessed, if you're an admin, via the browser by navigating to /_catalogs/users/simple.aspx from your site. For example, like this: https://intra.zimmergren.net/_catalogs/users/simple.aspx.

Updated 2019: This works on SharePoint 2007, SharePoint 2010, SharePoint 2013, SharePoint 2016, and SharePoint 2019.

In SharePoint 2019, the User Information List looks like this:

User Information List in SharePoint 2019 - showing the users on this specific publishing site.

In SharePoint 2007, the User Information list looks like this:

SharePoint's hidden User Information List in SharePoint 2007 (WSS and MOSS).

Oh, the memories of WSS 3.0 and MOSS 2007.

Write code to interact with the User Information List.

If you want to interact with this list to set properties on a user (In my case, I'm doing this, and I'm using WSS 3.0 at the writing of this post) you could do it like this:

// Instantiates the User Information List 
SPList userInformationList = SPContext.Current.Web.SiteUserInfoList;

// Get the current user 
SPUser user = SPContext.Current.Web.EnsureUser(@"ZIMMERGREN\TobiasZimmergren");

// The actual User Information is within this ListItem 

SPListItem userItem = userInformationList.Items.GetItemById(user.ID);

The above code will give you the SPListItem object, which links to the currently logged in user (the one executing the request).

You can then work with the SPListItem object like usual to get or set the properties like this:

string pictureURL = userItem["Picture"].ToString();

User Information List Fields

Instead of writing out all the fields/columns available, you can create a new Console Application and insert the following code to output all the fields names and internal names:

SPWeb web = new SPSite("https://intra.zimmergren.net").OpenWeb();
SPUser user = web.EnsureUser(@"ZIMMER\tozi");
SPListItem item = web.SiteUserInfoList.Items.GetItemsById(user.ID);

foreach (SPField f in item.Fields)
{
  // Output on all the existing fields
  // and gets their InternalName as well
  System.Console.WriteLine("Title: {0} -- {}",
    f.Title,
    f.InternalName);
}

Note: You will, of course, have to change the URL and User LoginName.

Thank you for reading

While this post was originally authored in 2008, the User Information List is still there, and still has purpose. Things have changed, and there are other ways to interact with the list today.

Enjoy.