IBT Number – Using Form REG-1 To Get An IDOR Number Chicago Illinois

Your IBT Number or Illinois Business Tax Number is an eight digit number used by an entity to pay taxes into the Illinois Department of Revenue Chicago Illinois. Just because your company is set up as a legal entity inside the State of Illinois, does not mean that you actually have an IBT Number. Many of my new customers have operated successfully in our state for many years, without having one. This is primarily because…


1 – Your Illinois Business Income Tax Return, can be filed successfully using only your Federal EIN.

2 – In order to have an IBT assigned, you must first request one from the Department of Revenue.


This is done by completing a Reg-1 Form and filing it with the state. Be careful when filing out this form. It asks very specific questions about the type of business that you are conducting, the types of taxes that you will be responsible for, and when you became responsible for those taxes. If you fill out the form incorrectly, you may have some difficulties. Examples would be…


1 – If you fill out the form and say that you will have employees beginning at a certain date, they will be expecting employment tax returns beginning on that date. If you do not have employees by that date and do not file the IL-941, the IDOR will still be expecting that employment tax return.

2 – The same thing will occur with sales taxes or any other tax that is collected by the state. If you register incorrectly, The Department will be expecting those returns and the accompanying taxes on the date that you specify.


In extreme cases, this can lead penalties and improperly assessed taxes.


If you have any questions on how to properly file this form or how to fix one that has been improperly completed, please don’t hesitate to contact us.