I am having trouble finding a replacement filter (reached 0% last week). Amazon is out of stock (and has some chinese knockoffs available). Philips IT is also out of stock, and Galaxus says a month+ delivery...

Of course, basically no problem. I had only ordered one filter via Amazon and it wasn't quite right. According to Philips, it was not entirely clear whether it had been stored incorrectly. For this reason, and because it makes no difference to the price, I only order directly from Philips. In general, you can of course buy the filters anywhere. Only the type designation must be correct.