Punching is a critical design case for reinforced concrete flat slabs but the provisions for punching shear design and detailing of the shear reinforcement differ considerably among the various European and American design codes. Therefore the thickness of the slab or the amount or distribution of shear reinforcement may vary between different countries. The punching shear capacity of concrete, the punching shear resistance with shear reinforcement and the relevant detailing provisions of four European, two American codes and the CEB-FIP Model Code will be compared. The provisions have been compared by analysing flat slabs with typical dimensions and reinforcement ratios. The possibilities and limitations of each code and the consequences in practice will be demonstrated, using the flat slab of an office building as an example. With regard to practical aspects, the importance of shear reinforcement that can easily be installed will be emphasised.