The inks are compatible with the P800 and the cart dimensions are too. The chips are the problem.
If you have never put third party chips in your printer, you can get a set of P800 third party chips on the open market and they will work for 1 time and that's it. Currently, all SureColor printers only take one time chips because the printer requires unique serial numbers for every new cartridge. So right now, there is only 1 set of serial numbers available on the market. We're investigating this intensely like we do, but for now, your solution is only partial.