HM Passport Office (HMPO) is urging travellers with upcoming trips to take a moment to carry out one vital check.

The office serves as the sole issuer of UK passports for British nationals, and also oversees registration services such as births, deaths, and marriages.

And in an update on X, formerly Twitter, HMPO officials issued a warning to anyone with a holiday booked. HMPO said: "If you're travelling soon, take a minute to check your passport expiry date. If you need to renew, you can apply online."

Text on a graphic accompanying the alert simply added: "Check your passport is valid before travel."

Each country carries its own entry requirements, and if your passport is invalid you risk being turned away at the airport.

Passports issued after 2018 remain valid for precisely 10 years. However, if your passport was issued before September 2018, it could remain valid for up to 10 years and nine months.

This is due to the previous practice where the passport office would transfer up to nine additional months from your expiring passport onto your new one.

As a result, some travellers hold passports that haven't technically expired and are still acceptable for international travel. The key exception relates to European travel, where passports must have been issued within the last 10 years.

For travel to the Schengen Zone, your passport must have been issued less than 10 years before your departure date, and remain valid for at least three months beyond your intended return date.

It is also important to bear in mind that, following Brexit, you are now limited to staying in Schengen countries for no more than 90 days within any six-month period.

Before Brexit, no such restrictions on the length of your stay existed.