"Some things are not straight forward.  The only thing that is true is that high value antiques may have been formally given in a will but that should not be taken for granted."

I'd go even further and say that in the case of inherited lower value items that have become collectable or collections that span decades of a persons life, "Most things will not be straight forward", at least for the immediate future.

For two reasons.

1.  That it is only since the growth of the inter-net that widespread trading of inherited or collected items could be undertaken by most people at a level that could be described as 'a business'.

2.  That HMRC now has the technology to trace business activities that previously it could not.

The situation has arisen because the present owners of such items now constitute a huge backlog, for which the previous rules no longer apply.  They are now subject to a new set of rules requiring paper trails or proof of purchase which were not required in the past and which are now impossible to obtain, to prove to HMRC how long the owner has had them or that they were not acquired for the purpose of trading.

I wonder how many stamp collectors, selling off a life-long collection, or someone selling off the contents of deceased family members homes would, in the past, have faced any questions at all once probate was granted?  My feeling is that once any IHT necessary was paid, HMRC closed the book on the matter.

The new reporting rules, IMO, are a major change in the way that HMRC views the sale of personal possessions.  Previously, unless there was blatant tax evasion, it took little or no interest.  Now, with their growing ability to track financial transactions, their interest is growing, as is their need to collect more tax revenue.

We have yet to see how HMRC will react to the flood of information it will be receiving, but I think it would be prudent for anyone who collects to start keeping receipts, just in case HMRC takes an interest if they start to sell any part of it.  I've kept receipts for the few additions to my glass collection I've made since the rules were brought in.  They will at least prove that I've had 'pride of possession' for (hopefully) a good few years before sale and may prove that I made no taxable profit if I do sell them.

In the way of most taxes I expect these rules will be elaborated on.  Possibly if the consequences are challenged in court, which I think they inevitably will be.   Some of the elderly can be remarkably stubborn when their rights are threatened and 'the optics' of pensioners dragged into court accused of tax evasion for selling granny's crockery or the stamps they collected from boyhood will prompt judges to demand clarification or throw out some cases.

Either way, there is more to come on this story and it's best to be prepared as well as possible.