The story then went viral, and was picked up by a range of media outlets across the globe.
Ms Crompton explained it was introduced because employees were often expected to socialise with clients at work events outside of business hours, and because most traditional flexible work arrangements benefited working parents and not employees without children.
"We wanted to offer something to younger Millennials who typically go out midweek and do the pub quiz. My team book a hangover day in advance, if they know they are going out," she told the BBC.
"If people used it two or three times a week and missed important client meetings then we'd have to have a think. But everyone has been really respectful of it so far.
"It's basically a work-from-home day, but we've sexed it up a bit to appeal to the younger generation … It promotes honesty as well."
Ellie Entwistle, who works at The Audit Lab as a PR manager, told the BBC she had taken a hangover day recently after drinking on a date night with her partner and then meeting up with friends after.
She said her colleagues respected the policy and that it promoted honesty.
"Everyone is pretty much the same, they take them as and when they need them, no one really takes the mick or takes too many. Everyone just used them when they're needed," she said.
The 19-year-old said she would have been "embarrassed" if she had to call her boss and pretend to be sick.
"If I'd had to ring her and pretend to be ill I would have felt really bad every time I saw her and would have had to keep up a lie," she told the BBC.
According to CNBC, the hangover policy is just one of many ways The Audit Lab promotes staff work/life balance, alongside main working hours of 10am to 4pm to help working parents managing the school drop off and pick up.
"I think it shows that you don't need to be watching someone work all day every day to know they're working," Ms Entwistle told CNBC.
"If the results are good and they're hitting targets, it doesn't matter that they're a bit sleepy one day working on the couch."
The policy has struck a chord with workers across the globe, with many taking to social media to praise the concept.
"This young boss has got it right, shame others don't follow suit. It is better to work from home and do something than call in pulling a sickie and do nothing!" one Twitter user posted, while others described it as "forward thinking" and a "great idea".
But it's not just The Audit Lab that boasts enviable working conditions.
Earlier this year, news.com.au reported on accounting giant Ernst & Young's groundbreaking Life Leave policy, which allows staff a staggering 12 weeks off per year, which can be taken in one or two blocks of time.
That extra, self-funded annual leave can be used for travel, relaxation or any other purpose, and the company has also rolled out other options including term-time working for busy parents and temporary part-time stints.
And Aussie innovation consultancy Inventium also made headlines across the world several years ago following the introduction of an unlimited paid annual leave policy.
Founder Amantha Imber said while some critics initially dismissed it as a gimmick, staff now took five-and-a-half weeks paid annual leave a year, well over the national average.