To comply fully with The Money Laundering Regulations - since 1st April 2014 administered by HMRC as that is when the Office of Fair Trading ceased to exist - several Judges have ruled that an Estate Agent (or a Business-sales agent) should comply with "Customer Due Diligence" measures to check the beneficial owner(s) of a business and to check that such people are who they say they are (an identity check) BEFORE establishing the business relationship, So if you get a telephone, e-mail or paper-based request to send or show your identity documents after signing an agreement, that is not in full compliance with the Regulations unless the Agent has given a 14-day Notice of Right to Cancel and the checks on your actual copy identity documents are carried out within that time with your full permission. Electronic checks without your permission breach your right to privacy and do not prove that the person checked is the signatory of the 'agreement'.
The Agent should not deny your right to cancel just because the Agent ASSUMES that you are not a consumer. Technically you, the individual signee, as a "natural person" are not the business entity itself and some judges have ruled absolutely that your cooling-off rights should not be denied. When a Notice of Right to Cancel is absent, you have a further full year during which you may cancel. That is particularly the case when you have signed away from the Agent's offices, and even more so if you signed at home.
If you want to complain to an Agent you cannot rely on doing so just via a telephone call, you need to complain in writing by Recorded Delivery (Signed For) and ensure your full correspondence address is at the top of your letter, followed by the current date and the Agent's address. If you get no satisfactory response within a few days, complain to The Property Ombudsman (TPOS) whose Code of Practice the Agent should be following. Complain (1) If the Agent has no visible Complaints Policy on their web-site; (2) if the Agent does not display a Redress Scheme logo e.g TPOS, NFoPP on their site and on their correspondence; (3) If the correspondence you receive is rude, condescending or threatening. Consider also complaining to your Member of Parliament.