Payment of the Issue Fee
When the patent examiner is satisfied that the patent application meets all of the requirements for patentability, the examiner will issue a Notice of Allowance. The applicant will be given three months from the date of the notice to pay an issue fee. If the issue fee is not submitted in time, the application will be regarded as abandoned. However, the patent office may accept a late payment of the issue fee if the delay is shown to be unavoidable.
The patent is issued as soon as possible after the date of payment, dependent upon the volume of printing on hand. The formal patent certificate is then mailed to the inventor's patent attorney. When the patent is issued, the patent attorney and the inventor should review the patent for errors. Errors in the patent can usually be corrected through the issuance of a Certificate of Correction.
A person who makes or sells patented product should mark that product with the word "Patent", or the abbreviation "Pat.", followed by the patent number. Frequently, the phrase is preceded by a country indication, such as "United States Patent 9,000,000" or "U.S. Pat. No. 9,000,000." A patent holder may not recover damages from an infringer unless products produced under the patent were properly marked, or unless the infringer was duly notified of the infringement and continued to infringe after the notice. The marking of an article as patented when it is not patented is against the law and subjects the offender to a penalty.
Some persons mark articles sold with the terms "Patent Applied For" or "Patent Pending." These phrases have no legal effect, but only give information that an application for patent has been filed in the Patent and Trademark Office. False use of these phrases or their equivalent is prohibited.
All issued utility patents are subject to fees that must be paid to maintain the patent in force. These fees are due at 3-1/2, 7-1/2 and 11-1/2 years from the date the patent is granted and can be paid without a surcharge during the "window-period" (the six month period preceding each due date). The maintenance fees may be paid up to six months late with the payment of a surcharge. Failure to pay the current maintenance fee before these deadlines may result in expiration of the patent.
There is no need to pay any maintenance fees in the United States for design patents. Design patents will always extend for their full 14 year duration from the date of issuance.