Trademark maintenance involves actions that people or businesses take to keep their registered trademarks valid. Trademark maintenance generally consists of one or more of four elements, viz., payment of renewal fee, issue of a cautionary notice, submission of an affidavit of use, and docketing of proof of renewal of basic registration.
• The payment of renewal fee is generally performed every ten years (10) from the date of registration.
• A cautionary notice is uTrademark protection is potentially perpetual, as long as it is being renewed and commercially used. The process of renewal needs to be started six months before the expiry of ten year period from the date of registration. 

A Statement of Use (SOU) is one of the official forms used by the Patent and Trademark Office. It can only be filed once a business has started to use a trademark. This means you can't register a trademark just to tie it up; you need to use it in commerce. Ways to prove a trademark's use include displaying it on products, packaging, or other marketing tools.
If you filed your trademark on the basis of intent to use, you must file a Statement of Use to show you are using it to sell goods and/or services. If you aren't ready to file the SOU, you need to file a Request for Extension of Time to File a Statement of Use within six months of when your Notice of Allowance was issued. The extensions can be filed every six months for up to 36 months.