Emily Coltman, chief accountant to FreeAgent, believes people who had to submit a self-assessment return on 31 January this year will have found an "additional complication" from Bitcoin.
"Some investors in the cryptocurrency will have taken advantage of its high valuation to cash out their investments."
George Bull, senior partner for RSM UK, comments: "Not withstanding the recent reduction in Bitcoin values, HMRC must be rubbing its hands in glee.
"With Bitcoin values having soared to record levels [in 2017] and many owners having sold out, sooner or later the taxman will be collecting his share of gains made from this cryptocurrency and from the hundreds of others following in the wake of Bitcoin."
HMRC and the IRS have issued guidance and frequently-asked-questions about cryptocurrencies on their websites. As Mr Futter comments: "There are inherent risks in investing in this space and identifying red flags to look for."
Is there a tax liability, however? Mr Bull states: "It all depends on how you acquired your coins. Most users will have paid for them in their digital wallets, and exchange these for traditional currencies, goods and services.
"However, some users, generally referred to as miners, amalgamate and verify transactions for others and receive Bitcoins for this service, along with any transaction fees offered by these parties."
This would be classed as an income, rather than capital.
So, what sort of tax will your clients have to pay if they have invested in cryptocurrency?
1) Capital gains tax
Although there does not seem to be a definitive answer yet as to how HMRC will treat those who cashed out this January, the most likely tax to which those making a capital gain on their initial investment will of course be capital gains tax (CGT).
Ms Coltman says: "I would urge anyone who has made money from [cryptocurrencies] to contact HMRC directly to check whether they need to include such information in their self-assessment tax returns or in a different capacity."
Those who acquired coins as investments when exchanged for traditional currencies, goods and services, will generally be taxed as capital gains, says Mr Bull, so CGT will apply to individual users.
2) Income tax
Those individuals mining for Bitcoin or buying and selling it as a trade will find any profits and gains chargeable to income tax for individuals, based on whether they are a lower-rate taxpayer or a higher-rate taxpayer.
