The impact of photon recycling (PR) and of luminescent coupling (LC) on the photovoltaic performance of all-perovskite tandem solar cells is analyzed by the means of optical and full opto-electronic device simulation. Optical processes are assessed using a comprehensive Green function formalism that considers wave optical effects also in emission. Starting from a consistent fit of experimental sub-cell and tandem characteristics, the effects of re-absorption are propagated from the optical limit to a situation with consideration of realistic charge transport across the entire tandem device. This also provides insight into the origin of performance losses due to sub-cell and interconnection quality.|Photon-recycling (PR) and luminescent coupling (LC) in all-perovskite tandem solar cells are quantified using a Green's tensor model for internal emission and re-absorption coupled to charge transport simulations. This enables the assessment of the upper limit of performance enhancement by PR and LC and of its quenching by optical and and electronic losses such as parasitic absorption and non-radiative recombination.image (c) 2024 WILEY-VCH GmbH