Full-time UK workers are legally entitled to at least 28 days annual leave, according to national employment regulations.

However, contrary to what many people think, employees can't always take their annual leave as and when it suits them.

Here's a quick guide to the scenarios where their annual leave request might be denied.

Refusing a holiday request

Employers often wonder can you refuse a holiday request?. The answer is yes, but they need to make sure they've got a valid reason for doing so.

For example, they can refuse a holiday request if it wouldn't be practical or convenient for the business, such as at a busy time of year, or if it would cause understaffing.

Some employers also restrict how many days off staff can take at once, so a holiday request may be refused if an employee asks to take their entire annual leave at once. There might also be restrictions on how many staff members can be off work at any one time.

In some cases, employers can force staff to take their annual leave at certain times of the year. For example, teachers have to take their holidays outside term time.

Although managers aren't obliged to state why they've refused a holiday request, it's always good practice to provide a valid explanation. If they clearly outline in their employment terms and conditions situations when holiday requests might be refused, they've got grounds to back up their argument.

Things must be kept consistent, however. If management refuse a holiday request to one member of staff, but not another, it could be seen as discriminatory. And that could be grounds for legal trouble.

Notice period

Employees who resign and request annual leave during this period can also have their request turned down, especially if they don't have enough accrued leave to take.

Managers can still refuse the holiday request even if an employee has sufficient annual leave, but they'll have to provide payment in lieu.

Where staff have used up more leave than they've accrued, the company is entitled to deduct the difference from their final pay packet.

Regulations

When employees can take their annual leave - and how much notice needs to be given - is dictated by the Working Time Regulations 1998.

These rules state that employees must give notice of their holiday request of twice the amount of time as the total length of holiday requested. So, a request for seven days off work will require a notice period of at least 14 days.

(The smaller and less formal the company, the more likely they are to bend these rules a little, as late requests cause less administrative hassle - but it's best to assume everyone goes by the book.)

Employees shouldn't book any travel or holiday arrangements until the request has been approved, as they won't be entitled to any compensation if the request is later refused.

Employers are also obliged to provide notice of a holiday request refusal, based on the regulations. This is equal to the same amount of time that an employee has requested off work. For instance, if a staff member asks for two weeks leave, an employer must give at least two weeks notice to inform them that the request has been declined.

Although workers are well within their rights to refuse a holiday request, managers must remember that staff are legally entitled to take their holiday allowance at some point during the year. To maintain good staff relationships and boost morale, it's preferable to accept holiday requests as far as is reasonably possible.