The dashboard tells you when they're not working in the Octavias. The H7 headlight ones are the only ones I've replaced to date in the MKIII. The MKII had indicator bulb(s) fail the NCT because the orange coating wore off the bulbs but that (on its own) is a free retest.
I don't bother checking anything for the NCTS. In all the years since NCTS took over from the CO I've only had one chargeable retest for the then licensed taxi - when the MKII required some suspension component or other. At €28 it's pretty good value for money. I daresay a main stealer would charge a damn sight more for such an inspection and would most likely take the piss with any resultant requirements.