Many thanks for your patience. The first thing to consider is that you, as an employer, have the legal right to refuse a holiday request by an employee. Therefore, if you have a number of employees all wishing to take their holidays at the same time, you can reject as many of these as necessary to ensure that the business is not adversely affected.
If that means that some employees cannot take their full holiday allowance before the end of the holiday year, then the following considerations would apply:
A recent European case confirmed that in these circumstances the employee does not lose their entitlement to leave and the employer will have an obligation to remind them that they have the outstanding leave in place. If the employer reminds the employee but the leave remains untaken, they may lose it, but if the employer does nothing and the leave is not taken, the employee should be able to carry it over.
However, that does not mean an employer can unreasonably refuse holiday requests over the whole holiday year and deliberately prevent someone from taking holidays at all. The tribunal said that employers should not exercise their right to reject holidays unfairly. If there are legitimate reasons for refusing holiday requests they may do so even if the employee ends up losing part or all of their annual holiday allowance, but if rejects are being rejected indiscriminately or deliberately, that would be unfair.
You could still come to an arrangement that whoever has not taken their full allowance this year because you could not approve it due to other requests at the same time, you would allow them to carry it over, but for next year they should not leave it that late or they would lose it.
Does this answer your query?