Whenever we create a new Facebook fan page, then Facebook gives an unique ID but when you change it to username then you will be not able to see your Facebook fan page ID anywhere around your Facebook. we used to find that id through Facebook graph API and also used Facebook ID finder online tools. but now you don’t have to go anywhere and not need use any third party tool to find your Facebook fan page ID.
Now, your Facebook fan page ID can be found under your Facebook page settings yes, now its available by the Facebook officially. may be it available from some times ago but this isn’t announced yet anywhere.
I just go trough Facebook to create a new page for my newly blog and found the option of Facebook page ID and without waiting jumped to write about it here. :)
To find your facebook page ID you have to go to your Facebook page which you want to find the ID.
Now, Go to Edit Settings > Page Info > There you will see several options of setting up your Facebook fan page such as Name, Username, Description, about, website information, etc. and at the last option you will enable to see your Facebook fan page ID that you can use to copy and paste anywhere you like. for the more information see the screenshot below.