Generally, it is a good idea to start the renewal of a trademark six months before it expires. But even if you miss the window, don't worry - renewal is possible up to six months after the expiry date. However, renewing a trademark after expiration may include additional conditions and cost extra, so this option should be saved as a last resort.
Since renewal extends your trademark's validity by another ten years and since it's a relatively simple process (no assessment of the mark is needed), it's definitely worthwhile, even if you are not using the trademark at the moment.
Renewal can be requested by you or your legal representative. You can use the services of the representative who filed your original application or take your request to someone new. At Trama, we offer a very straightforward way of renewing your trademark online.