Original poster lives in the UK.
I do know that you have periodic MoT inspections. The place to ask this question, is your friendly local MoT inspection station.
Technically it should be a violation, because the drop-in-replacement LED headlight "bulb" that you have, is not the correct type-approved light source for that housing.
What none of us can possibly know, is whether your friendly local MoT inspection station cares, and whether your local constabulary care.
Around here ... which is not the UK! ... as long as what you have is "reasonable", it won't be a problem. In this particular case, if you have a *good* LED (or HID) replacement bulb that has a proper beam pattern that doesn't excessively glare into oncoming drivers' faces, and you properly dip your headlights to low beam when there is oncoming traffic, it is exceptionally unlikely that you would draw any sort of the wrong kind of attention to yourself. On the other hand, if you have headlights that emit excessive glare on low beam (due to mis-aiming or due to the light source being "too cheap to be good") and you meet a copper on a dark road at night, there is a fair chance that he'll spin around and pull you over, initially for "failure to dip headlights" and then turn up your illegal modification which then, if you are exceptionally unlucky (or lippy to the cop, i.e. you fail the attitude test), turns into the copper pulling your plates and having the vehicle towed with you charged for "operate unsafe vehicle". Doesn't happen often, but it could ...