Can you define 'Serial Flipping is trading', and how that equates to 20% tax please, I am curious as I have never experienced this.
For example, If I buy a car for £1000, service it, give it a thorough valet and sell it for £2000 as a private individual I do not pay tax on this transaction and I can do this a number of times during the year and end up with a better car than the one I started out with if I trade wisely. My activities may raise a question at the licensing centre but otherwise I am doing nothing wrong.
However if I make my living buying and selling cars then yes I would have to pay tax on my earnings once I go past the tax threshold.
Does the same not apply to buying and selling a watch or watches?