This week's opinion

Last week I discussed the legal basis of Making Tax Digital (MTD). But there is an important practical issue to consider: the way HMRC retains MTD data both its own internally generated information and that provided to it by taxpayers.

There have been several cases in recent years in which the proceedings have been hampered by an inability on either side to produce copies of the documents that HMRC’s systems have generated. In R (on the application of William Archer) v CRC which involved tax and interest in excess of £20m there was a dispute about precisely what the taxpayer’s self-assessment online account showed on a particular day.

The agent had not kept a copy and HMRC’s systems were also unable to produce one. Thus on a matter of crucial importance the High Court judge had to make inferences as best he could in the absence...