This is the home page of Companies House, with a prominent red warning on the right hand side "Warning about bogus emails.
This the Security Page from HMRC (Her Majesty's Revenue & Customs) with information and advice about bogus emails.
I therefore conclude that bogus Phishing emails purporting to come from them are not exclusive to me......
Those cautions are pretty standard fare. I don't know of any bank, for instance, that doesn't provide the same or similar warnings.
Don't overlook an important wrinkle....you get the Phishers contacting you shortly after you contact these organizations. I don't think it's an aspect you want to ignore.
However, both of those sites offer a service you should use. They each ask that, if you get phishing emails, forward them to the addresses they provide. When they receive an offending email from you they will have a team track the phishers down and take action.
You should first expand the offending email headers to "long headers" as they contain a lot of helpful data that the team will want to see. It would be meaningless to you or me, but it is gold to them.
If you don't use the service (help) that these organizations offer, you can't really complain about the problem.