A trademark owner cannot add any designated goods and/or services to the trademark registration, because that broadens the scope of the designated goods and/or services. However, one or more designated goods and/or services may be deleted at any time, because that would disclaim part of the trademark rights and reduce the scope of the trademark.
In order to obtain trademark protection for new designated goods or services that would be beyond the original scope of a registered trademark, it is necessary to file a new trademark application for them. However, this will result in two trademark registrations, and because they would differ in regard to their respective designated goods and expiration date, this can be troublesome.
But, depending on the remaining duration of an already registered trademark, it is possible to file a new trademark application for designated goods or services that would included those of the already registered trademark, and to not renew that registration. To obtain more information about doing this in a specific situation, please contact us here.