I will present new results from a study of non-equilibrium chemistry in exoplanet atmospheres under conditions relevant to highly irradiated exoplanets. I will show the effects of vertical mixing and photodissociations on the chemistry and the subsequent impact on the temperature structure and on the spectra of these hot atmospheres. Non-equilibrium chemistry can introduce important differences to the calculated transmission and emission spectra that must be considered when analyzing observational data. We have developed a 1D radiative-convective atmosphere model, called ATMO, which couples consistently hydrostatic equilibrium, radiative transfer and equilibrium and non-equilibrium chemistry. I will also briefly discuss our current developments, the implementation of our non-equilibrium chemistry code in the Met Office UM, a sophisticated general circulation model (GCM), an important next step in understanding the inherently non-symmetric atmospheres of close-in, tidally locked planets. Our model includes non-equilibrium chemistry allowing us to consistently calculate the pressure-temperature profile. Previous studies either assume chemical equilibrium or do not allow non-equilibrium chemistry to feedback on to the background atmosphere, and none so far have included chemical kinetics in a 3D GCM.