In this paper, we present the InPERC technology implemented into a multicrystalline silicon (mc-Si) solar cell production of a major Chinese cell manufacturer. Stable average efficiencies over 18% were demonstrated. Best average efficiencies of 18.4% were achieved on mc-Si solar cells without selective emitter with a best cell efficiency of 18.8%. To reduce the cost of ownership (CoO) of the InPERC upgrade, the annealing step after ALD of Al 2 O 3 was successfully skipped by integrating it into the direct tube PECVD without increase of PECVD process time. Furthermore, the Al 2 O 3 thickness was reduced to 4 nm and the etch removal for rear side smoothening to 2 µm without loss in efficiency. An InPERC module was subjected to accelerated ageing tests with stable results. In a CoO-comparison of different PERC routes, the InPERC technology showed the lowest total CoO and the lowest payback period of all investigated PERC candidates.