Let P be a partially ordered set, R a commutative unital ring and F I(P, R) the finitary incidence algebra of P over R. We prove that each Rlinear higher derivation of F I(P, R) decomposes into the product of an inner higher derivation of F I(P, R) and the higher derivation of F I(P, R) induced by a higher transitive map on the set of segments of P .2010 Mathematics Subject Classification. Primary 16S50, 16W25; Secondary 16G20, 06A11.