Mark Harries KC

Call 1995 | Silk 2019


Mark’s substantial experience in business crime has earned him a reputation as a “highly sought after white collar barrister” who is “an outstanding fraud lawyer.” He is a refined forensic strategist in complex, paper-heavy cases and his “first class client manner” makes him the ideal choice for senior corporate figures who demand an unparalleled level of service from a barrister who leaves no stone unturned.

Business & Financial Crime

In 2019, Mark defended a company director for tax evasion in a 6 month diesel fraud trial to be featured in the BBC’s documentary “Defender’s UK” in October 2020.

“Mark carries significant experience in white collar crime matters and is a robust advocate. He works tirelessly and meticulously to achieve the best outcome for defendants. He is often instructed on cases involving voluminous evidence. A keen strategist who identifies the issues quickly.”

The Legal 500 


Experience & expertise

The 2022 Chambers UK Bar Guide describes Mark as a “very shrewd and smooth operator” who is “extremely hard working and a great tactician.” He is “excellent on his feet” and “his timing is perfect.” Prior to taking Silk in 2019, he was a consistently ranked as a leading junior in the fields of both financial crime and general crime.

He has significant experience defending prosecutions brought by the National Crime Agency, its previous guise as the Serious Fraud Office and HMRC, in particular allegations of tax evasion and banking and investment fraud. He has defended in MTIC frauds, Ponzi frauds and boiler room frauds across a wide variety of industries, including the diamond trade, the wine industry, environmental research and the construction industry in addition to  frauds within financial and investment markets.

Mark’s clients are usually high net worth professionals, CEOs, company directors, accountants and traders facing allegations of fraud, corruption or embezzlement, for whom criminal proceedings are desperately damaging on a practical and career level, whatever the outcome of a trial. Mark prides himself on going above and beyond in properly resourced cases so that he can met and exceed the high expectations of the most demanding of clients whose reputation is on the line.

Mark is committed to the meticulous and thorough preparation of every case in which he is instructed and is adept at handling cases involving a very large volume of paperwork, distilling the important issues into manageable and comprehensible topics to be presented to a jury with clarity and persuasion.

In recent years, Mark has presented seminars on a number of topics relating to financial crime, including the hallmarks of fraud, with a particular emphasis on hedge fund and banking fraud.

Recent business crime instructions of note include:

  • R v W (Southwark 2023): Leading for the defence in the highest value cryptocurrency money laundering trial ever prosecuted in the UK.
  • R v DC (Wood Green): For the defence of a company director in a 6 month HMRC/Trading Standards prosecution alleging tax fraud committed by way of a diesel-bulking scam. DC was acquitted of over £1m worth of excise duty evasion prior to trial following evidential submissions made on his behalf causing a re-think of the prosecution case; at trial, he was acquitted of VAT evasion in respect of a company owing over a quarter of a million pounds of VAT and of that company’s fraudulent trading. DC was convicted of two lesser counts confined to a single company. Featured in the forthcoming BBC documentary “Defenders UK.”
  • R v CC (Blackfriars): For the defence of one of 3 brothers in a 6 month trial of 10 defendants centring upon an £11m diversion fraud, using computer malware to obtain millions of email addresses which were systematically hijacked and used to conduct a variety of internet frauds.  For press coverage, please click here.
  • R v GJ (Derby): Acted for the first defendant, a solicitor, in a multi-handed 9 week trial who was alleged to have run a “cash for crash” fraud through his law firm. 5 of the 7 co-accused ran cut-throat defences against GJ. They were convicted. GJ was acquitted of all counts. For press coverage, please click here.
  • R v MF (Southwark): Leading for a company director accused of cheating HMRC of VAT generated in a construction industry fraud. After negotiations with the Crown lasting almost a year, MF pleaded to substantive VAT Act offences and avoided imprisonment. Two others were convicted of conspiracy to cheat and imprisoned.
  • R v HS (Southwark): Leading for a bank manager acquitted of providing mule accounts for money laundering the proceeds of £33m Operation Kadenza diversion fraud.
  • R v SA (Woolwich): Acted for defendant accused of facilitating mortgage fraud by his sister and laundering the proceeds. Suspended sentence. For press coverage from The Times, please click here .
  • R v JC (Wood Green): Led junior for company director accused of £44m VAT evasion using payroll companies to pay temporary workers. For press coverage, please click here.
  • R v B (Southwark): Operation Evenbox – defence of Financial Director chartered accountant in 6 month HMRC prosecution alleging £300m illegal tax sheltering against context of international environmental and medical research. Please click here for press coverage from The Telegraph.
  • R v AZ (Southwark): Operation Hayrack – acted for a company director accused of bribing the deputy property manager of the Royal Household in return for service contracts at Buckingham Palace and St James’s Palace. AZ was the only defendant convicted of corruption to avoid immediate imprisonment. Press coverage from The Telegraph and BBC News.
  • R v G (Lincoln): Defence of former CEO and “Superhead” of a Federation of Academies accused of embezzlement of public money and manipulation of contracts to employ family members. 10 week trial in Lincoln in which the Crown called over 20 lay witnesses including several Heads and Governors, the Chairman of the Board, a solicitor and an accountant, each of whom were cross-examined with a view to demonstrating a politically driven campaign to discredit the defendant. Acquitted on all counts. Click here for press coverage from BBC News.


The Great Defender. The genesis of my ambition to become a barrister was when I read about Edward Marshall Hall KC as a wide-eyed 13 year old. Marshall Hall, “The Great Defender,” was an extraordinary barrister. He rose to greatness as the dramatic advocate who secured victory in trials most thought unwinnable, inspiring countless criminal barristers to the unwavering belief that even the most overwhelming case can be won with a magnificent closing speech. Sometimes that is true, but not in every case. A crucial part of my job is to make sure that nothing is left to chance or a closing speech.

My passion is advocacy. There are few moments in life that can compare with the adrenalin that I feel when I rise to my feet in a packed courtroom, about to perform a finely-crafted cross-examination of a crucial witness or to make a closing speech when a man’s liberty hangs in the balance. Time freezes in the moment of silence before I begin. It permits me the brief luxury of remembering how lucky I am to be there and how grave is the responsibility I am taking on. It is, quite literally, something that stirs my blood.

“When the stakes are so high, there’s no room for complacency, reticence or oversight.”

Advocacy is not about clever words or grand flourishes. Marshall Hall’s days are long gone. It’s not about who shouts the loudest. The best jury advocacy is built upon foundations of simplicity, clarity and common sense. Don’t raise your voice, improve your argument.

Hard truths are sometimes difficult to hear but my duty is to ensure that every defendant I represent knows in detail the strengths and weakness not just of the prosecution case but of their own. My role is to protect those I represent; there are times when I have to fulfil that by giving advice that is unwelcome but realistic and necessary. Ultimately, I think my clients recognise the benefit to them that comes from my giving them honest, objective and clear advice.

Criminal cases are life-changing, whatever the offence involved. Reputations can be shattered by even the most minor of convictions and families are torn apart by imprisonment. When the stakes are so high, there’s no room for complacency, reticence or oversight. I want to give my defendants confidence that I defend them as I would defend myself – with commitment, discretion and judgment – but above all, without fear.


“He is simply quality. In his paperwork and advocacy, he is brilliant.”
Chambers & Partners

“He is absolutely brilliant with clients, gives them confidence and gets to the issues really quickly.”
Chambers & Partners

“Mark is exceptional.”
Chambers & Partners