Fuel cell system

A fuel cell system (200, 300) comprising a plurality of cell units arranged in a stack (205), and a method for start-up of the fuel cell system. The method comprises, at start-up of the fuel cell system: heating the stack (205) to a first threshold temperature; providing an unreformed hydrocarbon fuel to the anode inlet (226) when but not before the stack (205) is above the first threshold temperature; recirculating anode off gas from the anode outlet (227) to the anode inlet (226) while providing unreformed fuel to the anode inlet (226); and drawing a current from the fuel cell system (200, 300) while recirculating the anode off gas. The method may allow start-up without requiring an external reformer or water supply. The method may produce water in the fuel cell stack (205), which is recirculated to the anode inlet (226). The recirculated water may allow reforming of the hydrocarbon fuel at a reforming catalyst positioned between each cell unit of the stack. Also disclosed is a method of shutdown.