A thermoplastic polyester composition comprises, based on the total weight of the composition, from 20 to 95 wt. % of a polyester comprising a poly(alkylene terephthalate); from 1 to 35 wt. % of a phosphorous flame retardant consisting of a phosphinate of the formula (I) [(R1)(R2(PO)—O]−mMm+  (I), a diphosphinate of the formula (II) [(O—POR1)(R3)(POR2—O)]2−nMm+x  (II), and/or a polymer derived from the phosphinate of formula (I) or the diphosphinate of the formula (II); from 0.1 to less than 20 wt. % of a copolyetherester; from 0.1 to 5 wt. % of an anti-dripping agent; from 0 to 4.5 wt. % of a reinforcing fiber; and from 0 to 5 wt. % of an additive selected from the group consisting of a mold release agent, an antioxidant, a thermal stabilizer, and a UV stabilizer.