How Many Sick Days Per Year are Acceptable in the UK

In the UK, there is no legal limit on sick days per year, but employers can set their own thresholds — often guided by the national average of around 4.4 days (per recent ONS data) — and tools like the Bradford Factor to monitor frequent short-term absences, whilst Statutory Sick Pay applies from day one for up to 28 weeks, after April 2026.

• How much time off sick is too much?
• What is an acceptable number of sick days?
• How many sick days are you allowed in a year UK
• What drives the 4.4 average sick days a year statistic in the UK?
• What are the calling in sick-to-work laws in the UK?
• Absence management

What is the average number of sick days per year?

First, let’s look at the current state of sickness absence. According to the latest sickness absence data from the Office of National Statistics (ONS) for the 2023/24 period:

• An estimated 148.9 million working days were lost because of sickness or injury in 2024.
• This is on average 4.4 days lost per worker.

How much time off sick is too much?

The first thing employers need to be aware of is this: they are free to set their own threshold for too much sickness absence.

Employers will differ in opinion, no doubt, and set their own sickness absence rate. However, there is no legal definition of how many sick days is too many in the UK.

Employers need to find a balance between being too lenient and too severe when dealing with sick employees.

What is an acceptable number of sick days?

We now know that there is no legal upper limit to the number of sick days employees can take. But how many days sick leave a year in the UK is acceptable?

There are many ways to determine an admissible amount of absence. Employers can determine this amount based on the average sickness rate in the UK (4.4). They can also determine it based on the average in their sector. It may also be deduced using business records on sick leave data.

However, there is a more reliable methodology for setting this standard which looks at the effect of absences in the workplace called The Bradford Factor. The Bradford Factor is calculated using the Bradford Formula S2 x D = B:

• S is the total number of separate absences by an individual
• D is the total number of days of absence of that individual
• B is the Bradford Factor score

The Bradford Factor allows managers to monitor absenteeism during any set period. Many companies identify a running year as an acceptable period. If the number falls within a certain range, it is worth exploring the reasons behind the absences.

We would recommend recording absence dates and the reason for absence. Conduct return-to-work interviews to collect this data. This method also works as a deterrent for unauthorised absence.

So, when you’re considering how many sick days per year is acceptable in your organisation, keep these methods of determining it in mind.

How many sick days are you allowed in a year UK?

As we've explained, there actually isn't a legal limit on how many sick days per year UK employees can take. However, there are rules on when staff are entitled to Statutory Sick Pay (SSP).

After April 2026, employers must pay SSP from day one of sickness absence. Once you start paying SSP, you must continue to pay it for up to 28 weeks of absence, as per the UK's regulations on sickness policies.

If employees are off work for a significant amount of time (long-term sickness absence), you may begin to consider a capability dismissal. If the employee has been absent for more than a month, it’s normal and reasonable to invite them to a welfare meeting. If an employee has breached the number of acceptable absences, then you can hold an absence review meeting. These meetings don’t have to be face to face.

In this meeting, you can discuss a phased return to work or temporary changes to the working relationship. It’s recommended you hold several of these meetings before considering a capability dismissal. It may be possible to agree to alterations to an employment contract and consider a part-time return with a pro-rata salary.

What drives the 4.4 average sick days a year statistic in the UK?

The figure above is the number of days lost per worker, per year on average during a normal working year. That may not sound like very much. But let’s look at this another way, as there are other ways to measure the economic effects of sickness absence in the UK.

For example, we could measure the average number of sick days per year in the UK as the total days lost. This number gives us a better indicator of how disruptive sickness absence can be. In this case, the latest ONS statistics tell us that an estimated 148.9 million working days were lost because of sickness or injury in 2024.

Another useful approach is to assess what is causing these absences. Usually, the top reason given when employees take sick leave is “minor illness”. This term captures everything from coughs and colds to sickness and diarrhoea. Minor illnesses accounted for 30.0% of occurrences of sickness absence in 2024, followed by:

• musculoskeletal problems at 15.5%.
• "other" conditions at 15.1%.
• mental health conditions at 9.8%.
• respiratory conditions at 7.3%.

Next on the list are musculoskeletal problems. This includes anything from back and neck pain to more serious disorders. Approximately 7.8 million working days were lost due to work-related musculoskeletal disorders (2023/24). Coupled with minor illnesses, these two issues are responsible for a statistically significant portion of absence in the UK in 2023/24.

The final reason for absence we’ll look at is mental health. This issue has become more of a focus for businesses over the last decade. As a result, employees are more willing to be open about their mental health issues. As it stands, the average number of sick days in the UK relating to mental health conditions is 17.5. Whilst this is lower than the other two reasons, it remains one of the leading reasons for sickness absence rates in the country.

Now that we have a better understanding of why people take time off, and what impact this has on businesses, let’s look at how we can address the issues.

What are the calling in sick-to-work laws in the UK?

Your employees will call in sick from time to time. Unfortunately, sick leave is often more complicated than expecting employees to return as soon as possible.

If your employee is away for longer than a week, you are allowed to expect a doctor’s note to support their claims. You should make this clear in your sick note rules.

You can also ask anyone with an absence for fewer than seven days to fill out a self-certification form. This is filled out in person on their return; to try to ensure it was not used for personal days.

There is also the requirement to pay SSP to employees from the first day of sickness absence, post April 2026.

To reiterate, calling in sick-to-work laws do not dictate how many days sick leave a year employee can take in the UK.

Statutory holiday entitlement is built up (accrued) whilst an employee is off work sick (no matter how long they are off). If an employee is ill just before or during their holiday, they can take it as sick leave instead.

An employee can ask to take their paid holiday for the time they are off work sick. They might do this if they do not qualify for sick pay.

If you dismiss an employee whilst they are in receipt of SSP, you must provide a SSP1 form which explains why you are no longer paying SSP. If the employee feels like they have been dismissed because they are ill or in receipt of SSP, they may be able to complain to an Employment Tribunal.

A note on disability and sickness absence

Under the Equality Act 2010, if an employee's sickness absence relates to a disability (a physical or mental impairment with a substantial and long-term adverse effect on daily activities), employers must make reasonable adjustments.

This may include discounting disability-related absences from trigger points or the Bradford Factor, allowing additional time off, or modifying roles/working arrangements. Failure to consider these could lead to discrimination claims. Always assess whether a condition may qualify as a disability and seek medical/occupational health advice where appropriate.

Get absence management advice

The unpredictability of staff absence means it can be quite a challenging task. Get expert support from Croner’s HR team by calling 01455 858 132.