Thread: 8 Month Old Kitten Urinating on Furniture .. HELP??!!

You say he is fine using the litter tray so my first thoughts are the type of litter you are using. Some litter materials can stick to the kittens feet and then go with them carrying the ordur which signals to them it's time to go...
This seem most likely as the areas they are urinating are places I imagine they may sleep for extended periods allowing the odour to sink in. Urine odours are notoriously difficult to shift even with off the shelf cleaners and removers and not only this but can serve to be another signal for the kitten to urinate just like the litter tray smells.

One tactic I used on one of my MC's when they were a kitten was to contentiously pick them up give them affection then gently place them within the litter tray. More often than not they would go and overtime become more use to taking themselves to the litter tray giving the areas they have urinated previously a chance to air out. I know this may be hard if you are away in the day but even just doing this in the evenings may serve to aid the problem along with experimenting with additional litter materials.