I think that may be a company policy rather than a legal policy. I work for a scottish company in scotland where I am a union rep. My holiday year follows the financial year (april 1 - march 31st) and secondly I do not lose holiday hours that I don’t take - that would be wage theft. In theory I can rollover holidays indefinitely but if I worked for a company that did not allow this, the company in question would effectively have to buy any unspent holiday hours from me. There is no use it or lose it, theres use it for time off or be paid for it.
Out of curioisity how many holiday days do you get per year?
And asking two people was easier than using a search engine?