Can't even get SIMPLE things right
They have a portal specifically for people who don't normally have any dealings with HMRC to submit ad-hoc Capital Gains returns.
Simple enough questions - what did you buy it for, what did you sell it for, what do you think the tax is that's due. But then it asks when did you buy it, and when did you sell it - and this is where it fails dismally.
What retarded, brain dead, useless cretin thought it a good idea to put a rule in that "the sale date can't be prior to the start of THIS tax year ? WTF ?
Apart from meaning that it imposes different timescales to other means of reporting, it makes it useless if (for example) you sold something during (say) March, and didn't get all the paperwork (eg final solicitor's bill) until (eg) the middle of April.
if they want people to do the right thing, then they need to make it easy to do the right thing.