i generally leave it. if it's just a rubble bag or two and they've been nice customers i might take it and then leave that on the next job. if you do take it with you, remember to get your waste carrier license or you could end up in serious trouble. get a license for your local tip. tell them it's domestic waste. i told them last year i was building an extension and they gave me two licenses - one for garden waste for twelve visits, and one for everything else, also twelve visits. the year before that i told them i was doing a loft extension. the blokes at the tip don't even bother stamping them.