A Part-FCL PPL holder may hold an FI certificate to instruct at up to PPL level. For PPL instructing he/she must have passed the CPL exams, but this is not required for instructing at LAPL level.
In either case, the PPL/FI may receive remuneration for providing flight instruction. This has been the case ever since the Aircrew Regulation came into effect in 2011...... Hitherto a R/BCPL was the minimum licence required for a pilot to receive remuneration, but this is no longer the case.