Home Postcode finder WA Sinclair Sinclair postcode WA Sinclair is a locality in Western Australia covered by postcode 6450. Postcode 6450 State or territory Western Australia (WA) Region Wa Subs 1 G Flds Add a free Sinclair business listing More business listings in Sinclair Businesses in SinclairEsperance Christian Primary School2 Blake St · 08 90712703 Common questionsWhat is the postcode for Sinclair?Sinclair, WA has the postcode 6450.What state is Sinclair in?Sinclair is in Western Australia (WA).Does postcode 6450 cover more than one suburb?Yes. Postcode 6450 covers 23 localities, so the postcode alone does not identify Sinclair. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.