Phil Davison-Sebry remembers feeling "physically sick" when he discovered the blunder that would end up killing his family's 134-year-old business.
Davison-Sebry was holidaying with his wife in the Maldives when he received a panicked call from one of his biggest clients back in 2009.
That was because the UK government's registrar of companies, Companies House, had officially listed his Welsh engineering firm Taylor & Sons as having gone into liquidation.
In reality, though, it was the similarly-named, Manchester-based company Taylor and Son Ltd that had gone bust.
And while the error took just three days to correct, the damage had already been done.
The news had spread, and it led to Tata Steel withdrawing its lucrative £400,000 ($765,944) a month contract.
Davison-Sebry also blamed the blunder on the loss of a potential deal with the Royal National Lifeboat Institute, which would have added £3 million to the company's coffers.
Two months after the mistake was originally made, Taylor & Sons, which employed 250 people, actually did go into administration.
Davison-Sebry sued the government over the mistake — a legal battle that took a painful seven years to resolve.
In the end, the British High Court awarded Davison-Sebry £9m in compensation.
Speaking to Wales Online recently, Davison-Sebry has finally revealed new details about the personal toll that one spare letter "s" took on his health and his family.
"We had a thriving business and a full order book," he said of the company before the typo. "We were on course for making £45m that year."
Luckily, no jobs were lost as Davison-Sebry was able to sell up to competitors.
These days, he runs several new businesses outside of engineering — but he said the loss of his family's company had been a huge blow.
"We kept telling people that we were not in liquidation but the credit references agencies denied it," he told Wales Online.
"I felt physically sick. Back at the business the phones were ringing out, it was like Armageddon. Everyone wanted to be paid. People were queuing up for money. Equipment was being taken off site I felt like I had been kicked in the b**locks.
"I haven't got the businesses back that I lost because they were sold out from under me."
Davison-Sebry said at the time he was mostly concerned for his staff as well as the wellbeing of his wife and daughter, who also worked for Taylor & Sons.
He said it had taken him years to recover from the trauma.
"Afterwards I was so down and so gutted that I was not in a good state. Looking back I should have started it back up the next day but I wasn't in the mental state to do it," he told reporter Will Hayward.
"I could hardly sleep for two years — I would wake up in a sweat."
Davison-Sebry, who lives in the Welsh capital, Cardiff, is now the group managing director at Taylor Group, according to his LinkedIn profile.
Last year, his son Thomas Sebry was nominated for an Entrepreneur of the Year award.