If you sell your home for 15% above your LPT valuation...


I think you're missing the point here. They're not saying being above 15% means you underdeclared! Everyone has to be able to stand over the valuation they put on their property. Revenue are simply saying if a subsequent sale is within 15% then as far as they're concerned that's not materially different. The alternative, in the absence of setting a threshold for accepted variation, is that on EVERY sale there would have to be clarification given... that would make no sense whatsoever.

If its more than 15% then they want to confirm that the original valuation was reasonable. Yours clearly was, so yet again I don't see your problem.