The cancellation of patent can be done under two circumstance and these circumstances includes:
- Surrender of the patent
The owner of the patent may surrender the patent to the Registrar of Patent (the Registrar) at the Business Registration and Licensing Agency (the BRELA) in which the surrender may be limited to one or more claims. The surrendered patent shall be accepted if its supported with a declaration by which the licensee consents to the surrender unless the licensee has expressly waived this right in the licence contract. When the said surrender is received by the Registrar he shall remove the patent from the register of patent and this leads to the cancellation of the patent.
- Invalidation of patent
An application for invalidation of a patent can be done by any interested person by instituting proceedings against the owner of a patent or in the proceedings instituted against any interested person by the owner of the patent request the High Court of the United Republic of Tanzania (the Court) to invalidate the patent. Upon the application made to the Court to invalidate the patent, the Court shall invalidate the patent on the following grounds:
- that the claimed invention is not patentable as stipulated under the law;
- that the claimed invention is not excluded from protection as stipulated under the law;
- that the description and the claims comply with the requirements prescribed under the law and the rules pertaining thereto;
- that the person to whom the patent was granted, had no right to the patent: and
- that the patent has not been assigned to the person who has the right to the patent.
If the request for the invalidation apply only to some of the claims or some parts of a claim, therefore the Court shall invalidate such claims or parts of a claim. The Court may require the owner of the patent to submit to it for the purpose of examination, publications and any other documents showing the prior art which has been referred to either in connection with an application for a patent or other title of protection filed, for the same or essentially the same invention, by the owner or the patent, with any other national or regional industrial property office, or in connection with any proceedings relating to the patent or other title of protection granted upon such application.
The notice of the request for the invalidation of the patent shall be served to the licensee under the patent and if it appears to the court that the right to the patent belongs to a person who is not a party to the proceedings notice of the request for the invalidation of the patent shall be served on that person who shall be entitled to join the proceedings.
When the Court issues an order to invalidate the patent or claim or part of a claim, it shall be regarded as null and void from the date of the grant of the patent and the decision of the Court is not subject to appeal. The Court shall inform the Registrar of its decision of invalidating the patent and the Registrar shall register the removal of the Patent from the patent register and publish its cancellation as soon as possible.
The infringement of the patent may be conducted by a person other than the owner of the patent and without the authorisation from the owner of the patent in relation to a product or a process falling within the scope of a validly granted patent it shall constitute an infringement of that patent. The infringement on the patent can be done by a person other than the owner of the patent if he does acts such as:
- uses the patent which has been granted in respect of a product
- making, importing, offering for sale, selling and using the product; and
- stocking such product for the purposes of offering for sale, selling or using;
- uses the patent which has been granted in respect of a process
- using the process; and
- doing any of the acts in respect of a product obtained directly by means of the process.
- uses the patent on the areas where the limitation of the right to use the patent is limited such as:
- The rights under the patent shall not extend to acts done for scientific research.
- The rights under the patent shall not extend to acts in respect of articles which have been put on the market in the United Republic of Tanzania by the owner of the patent or with his express consent;
- The rights under the patent shall not extend to the use of articles on aircraft, land vehicles or vessels of other countries which temporarily or accidentally enter the United Republic of Tanzania;
- The rights under the patent shall be limited by the provisions on the patent term; and
- The rights under the patent shall be limited by the provisions on compulsory licences for reasons of public interest or based on interdependence of patents and by the provisions on Government exploitation of patented inventions.
Once the rights of the licensor and the licensee have been infringed they may have a recourse to remedies such as: –
- to request for temporary injunction to the Court;
- request that the fact of infringement be declared by the Court;
- to request an injunction to restrain and forbid the person from further infringing the patent;
- to demand a declaration or other appropriate means from the infringer e.g. through publication of the declaration and at the infringer’s expense;
- to report the matter to the relevant authority in which the infringer will be liable to an offence and shall be liable to pay a fine not exceeding TZS five hundred thousand shillings (500,000) or imprisonment for a term of not less than five (5) years or both;
- to request the Court for forfeiture of the goods made through the infringements of the patent;
- to demand surrender of the enrichment obtained through the infringement;
- damages; and
- any other remedy provided for in the civil law.
 Section 63(1, 2 & 3) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 64(1 & 2) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 64(3 & 4) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 64(5 & 6) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 65(1 & 2) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 66 of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 36(a & b) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 38(1, 2, 3, 4 & 5) of the Patent (Registration) Act, Cap 217, R.E 2002.
 Section 67 & 70(1) of the Patent (Registration) Act, Cap 217, R.E 2002.