What not to do
"Whether it's avoidance or evasion, don't ignore HMRC," says Porter.
In evasion cases the key to keeping it in the civil arena is to work with HMRC, he says. For avoidance, an ongoing relationship matters. "You can expect a lot of scrutiny in the future from [HMRC] if you don't engage."
When engaging it is important not to provide information without any context. Firstly, it might contain information HMRC has no right to view, including about third parties, secondly it gives the revenue a chance to look at it through its own lens.
The result could be guilty until proven innocent rather than innocent until proven guilty, he says.
"If you've got context for something and why it happened, I think that can go a long way to explaining why it happened and de-escalate things.
"You have to recognise that you've got two angles to this, you've got the law and the facts and then you've also got the individuals on the other side of the table.
"It's just like building credibility with someone, if you lose the credibility and the revenue comes to their own interpretation of your facts, that's when it's very hard to dig yourself out of that hole. Whatever you do after that point, it's all coloured by what's happened before."
Opting for the 'safe' space
There is a sense the government is trying to collect more tax to make up for Covid debts as well as resume a backlog of investigations that were stood down during Covid, says Porter.
This means times are busy for HMRC. At the same time there are numerous exchange agreements floating around with other jurisdictions.
For Porter himself, who works with a range of large corporations as well as high net worths and smaller cases, his time is filled with sorting IR35 cases, pension trustee takeovers and SDLT transactions.
He believes there will be more scrutiny of large organisations going forward, as they are already being held responsible for their supply chains under IR35.
But he is doubtful as to whether HMRC has the resources to deal with its many avenues of tax information and investigation.
He describes the digital disclosure service, where people can voluntarily disclose tax mistakes as "a bit cumbersome" and "a round peg in a square hole".
Similarly, for larger businesses, which get assigned a customer compliance manager, there are often long delays between them interacting and getting a response from HMRC, he says.
"I'm not hearing anyone saying that the revenue is well resourced enough to do the job."
