A trademark owner is not required to voluntarily submit evidence of use while his/her trademark registration subsists. However, whenever a registered trademark, without justifiable cause, has been put to non-use for three consecutive years, or whenever, after a period of use, use of the trademark has discontinued for a term in excess of three consecutive years, the IP Office may, ex officio or at the request of an interested party, cancel the right to the exclusive use of the mark.