When you head off for a break this year, spare a thought for workers who have unlimited holidays.

Although having an endless allowance of leave may sound like heaven, in reality you would not be likely to spend half the year sipping piña coladas on a remote beach.

Bottomless holidays first appeared in the mid-90s, with IBM among the vanguard. Other technology firms in Silicon Valley, such as the job site Glassdoor, the business network LinkedIn and the streaming service Netflix, followed suit – and now unlimited holidays are spreading into British workplaces. Richard Branson’s Virgin Group introduced the policy in 2014 and tech companies such as Songkick, PR firms such as Golin and marketing agencies such as Visualsoft have also taken it on.

Firms that have introduced unlimited holidays claim the policy works wonders, helping their employees to create a better work-life balance. Having control over holidays is also said to make employees happier, which should make commercial sense, because happier workers are generally more productive. A flexible holiday policy could also help companies attract skilled employees, which is particularly important in industries where talent is scarce, such as software development.

The reality is often quite different. The package is limited to a tiny number of UK workplaces, usually in the technology and professional service sectors. The companies that offer it tend to be demanding and all-consuming workplaces, so taking time off can make employees feel guilty – particularly as it may show their boss and their colleagues that they are not fully committed. If you are up for a promotion against another colleague, it is unlikely you will book that two-week Himalayan trek. This means employees often end up taking less time off, not more.

In addition, it means firms do not need to account for holidays they would previously have owed to employees. It is workers who stand to lose; if they leave, they will not be paid for unused holidays. Not so heavenly after all.