The United Republic of Tanzania became bound by the PCT from 14 September 1999. This would appear to suggest that patent protection in both Tanganyika and Zanzibar can now be sought by way of a PCT application designating Tanzania, and this is the view held by WIPO. However, clients should be aware that uncertainty exists as to whether Zanzibar is bound by the United Republic of Tanzania Patents Act of 1987. If Zanzibar is not bound by this legislation then no mechanisms exist for entering the PCT national phase in Zanzibar. Clients would be advised not to place reliance exclusively on the possibility of a PCT national phase application for Zanzibar. Where possible an application for re-registration of a granted UK/EP patent in terms of the existing law should be made, until clarity is reached.

Tanzania became bound by the Harare Protocol of ARIPO on 3 August 1999. This means that PCT applications having international filing dates on or after 14 September 1999 may designate Tanzania for an ARIPO patent as well as a national patent. Once again, however, there is uncertainty as to whether an ARIPO patent can be valid and enforceable in Zanzibar in the absence of laws providing for substantive patent applications. Re-registration of a granted UK/EP patent is advisable where possible.