Verify the registration
On the public register, before booking.
Someone else dumped it. Under the duty of care, that can still be your problem.
The household waste duty of care is widely unknown and genuinely enforced. Pass your rubbish to someone who is not a registered waste carrier, and if it turns up fly-tipped in a lane, the penalty can be issued to you — because you did not take reasonable steps to check where it was going.
That makes two unglamorous documents the most valuable part of this service: a carrier registration you can verify on the Environment Agency's public register, and a transfer note naming the carrier and the destination. The cheapest quote in a van with no paperwork is cheap because it has skipped both.
The other thing worth refusing is work that needs a specialist. Asbestos, clinical waste, chemicals and gas cylinders all require licensed handling, and a general clearance firm that takes them anyway is gambling with its crew and with wherever that material ends up.
On the public register, before booking.
It is your duty-of-care evidence.
Asbestos needs a licensed specialist.
Free, after we have seen the job, with no obligation.