A study of 7,000 employees found restaurant, bar and pub staff are allowed to take up to 30 days a year but take an average of just 16.
While those working in quick food service venues can also book off 31, but only take 25.
In contrast, workers in the healthcare and medical sector book three days MORE than their 38.5 day allowance a year.
Experts analysing the data found those working in call centres also take very little holiday â just 19.5 days out of their 32-day allowance.
While at the other end of the scale, professional services employees â lawyers, accountants, consultants â take their exact entitlement.
Across all industries, the average person gets a leave allowance of 32 days (31.8) but only takes 27 (26.6), leaving a full week of time off (5.2 days) left unused each year.
The findings were published by online staff management company RotaCloud, which has created a tool allowing workers within different sectors to compare their holiday entitlement.
Pam Hinds, head of HR at RotaCloud, said: âEmployees should always take their holidays but as our annual leave tool has shown, many donât.
âThose working in hospitality in particular have had to work exceptionally hard to meet the requirements of the public over the last few years, usually doing long, antisocial hours, and covering days when many people are enjoying time off.
âWhile we have medical professionals who, according to our data, sometimes use more than their entitlement, and rightly so â no doubt to have rest days in order to cope with their incredibly stressful and demanding jobs.
Time off is necessary
The data found 69 per cent of workers didnât take all their annual leave last year, with some opting to lose out on days altogether.
While a separate study of 2,000 workers, also commissioned by RotaCloud, found 43 per cent are allowed to roll over any unused holiday allowance into the following year.
Having too much work to do was cited as the main reason why a fifth donât take all their entitlement.
While one in six donât trust there wonât be new Covid restrictions, so still donât want to take the risk to travel.
Having no one to hand work over to and feeling the hassle of coming back to a mountain of work prevent 16 per cent from using their allowance.
Holidays being too expensive, finding it hard to co-ordinate breaks with a partner and not wanting to leave colleagues in the lurch were also among the top reasons.
Sadly, more than one in 10 claim it is pointless taking holiday as theyâd only work all the time anyway.
However, of those who donât always have annual leave leftover, 38 per cent have been known to take MORE time off than normally allocated.
On these occasions, wanting to go away (39 per cent), unforeseen illness (38 per cent) and having to look after the children (34 per cent) were the main reasons.
While 33 per cent of those booking extra days have done so to look after their own mental health, while 31 per cent have needed to go to the doctor.
Across all respondents, polled via OnePoll, six in 10 believe they will burn out if they donât take all the annual leave allocated to them.
Pam Hinds added: âFifty-eight per cent of people think the amount of holiday days on offer is one of the most, or the sole most, important factor when deciding to take a job â yet weâre still not taking all of the annual leave weâre entitled to.
âNot only are you owed it by your employer, but taking regular breaks from work is vital, for both your physical, and mental health â so itâs really important to take your entire annual leave entitlement, no matter how busy it is at work.
âAs employers, we should be encouraging annual leave use to its fullest and actively ensuring that people feel able to, and comfortable, taking time off.
"Hopefully, our annual leave tool helps to highlight that we could all do with a bit more of a break.â
Sector                          Allowance       Used
Healthcare/ medical/ hospital                    35.0              38.5
Professional services                           32.5              32.7
Optical                                      32.9              31.8
Retail - online/ecommerce                       33.2              31.4
Veterinary and animal care                       30.7             30.2
Volunteer/ charities                             36.1              29.7
Entertainment                                 35.6              28.7
Dental practice                                30.5              28.6
Software/ technology                           33.6              28.2
Transportation                                33.1              28.0
Retail - store                                  31.3              26.6
Care homes/ residential care                     30.6              26.0
Quick food service                             31.3              25.3
ITÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 32.8Â Â Â Â Â Â Â Â Â Â Â Â Â Â 25.2
Other hospitality                              30.8              24.6
Catering/ events                              31.3              23.6
Leisure/ recreation                            30.6              22.9
Hotel/ resorts                                29.5               21.9
Call centre                                   32.0              19.5
Restaurant/ bar/ club/ pub                      29.8               16.4