Prior to opening a bank account, the corporation must obtain an Employer Identification Number, which is the corporate equivalent of a Social Security number. This is done by filing an IRS Form SS-4.
IRS Form 2553
If your corporation is to be taxed as an S corporation, you must file IRS Form 2553 with the IRS within seventy-five days of incorporation. As a practical matter, you should sign and file this at your incorporation meeting; otherwise, you may forget.
State Tax Forms
In most states, there is a state corporate income tax. In some states, you will be exempt from corporate income tax if you are an S corporation, but you will need to file a form to let them know that you are exempt.
If you will be selling or renting goods or services at retail, you may be required to collect state sales and use taxes. To do this, you will need to register, and in most cases, pay a registration fee. In some states and in some businesses, you will be required to post a bond covering the taxes you will be collecting. There may be other taxes that your state requires.