Catalyzes the decarboxylation of L-tyrosine to tyramine, which can be converted to the hydroxycinnamic acid amides feruloyltyramine and 4-coumaroyltyramine (PubMed:17763868). Possesses low tryptophan decarboxylase activity (PubMed:14535886). H(+) + L-tyrosine = CO2 + tyramine Belongs to the group II decarboxylase family.