If you own trademark registrations in the United States, you are required to make certain filings with the U.S. Patent and Trademark Office (PTO) to keep your trademark registration(s) alive. In particular, prior to the sixth year of registration, you are required to submit evidence to the PTO bthat the mark is still in use, and every ten years you must file a renewal to keep the registration active (Maintenance Filings). If you have engaged a law firm to handle your intellectual property portfolio, you may receive letters from the firm advising you of upcoming Maintenance Filings and requesting authorization to make such filings on your behalf. If your in-house counsel maintains your portfolio, that person should be aware of these filing deadlines.