MoneySavingExpert has revealed that a stealth rule change may mean that you were rejected from your flight at the airport.
Concerned for holidaymakers, the passport office has made a change.
It has always been clear that, when you renew your passport, the remaining time on your existing passport will be added to your new passport.
The Liverpool Echo points out that this can be up to nine months more valid for British passports that are renewed before the expiry date.
For example, a traveler whose passport expires on June 1, 2019 can renew on September 1, 2018 and receive a new document valid until June 1, 2029.
But in alarming news this is no longer the case.
When MSE phoned the customer service number of the passport office, they were told that a new policy had been introduced from Monday 10 September and that the validity is no longer being transferred.
The biggest problem with this is that many countries, including Dubai and Turkey, will not allow you if you have been in your passport for less than six months.
The founder of MoneySavingExpert, Martin Lewis, said: "The biggest problem here is that many countries will not let you in if you have been in your passport for less than six months.
"In fact, we've heard some stories about people being sent home because a child's passport is too close to the expiration date.
"This policy change will lead many people to renew later so that they can scrape their passport every last month.
"But that of course runs the risk that many more people will be returned home.
"And it seems that the government has chosen to do this without informing people and putting such a big change in place in the hope of sneaking under the radar.
"They have failed to sneak under the radar – so they will probably have to officially announce it now.
"This change will affect the price, because passports will only last nine and a half years.
"But it also runs the risk of more people being sent home, destroying holidays and putting many people in a worrying situation.
"Because of the timing, which actually means that this shortening will take place during the Brexit period, chances are that we will see an even higher build up of the demand for the next summer, when there are already long waiting times.
"I do not know if this is a decision by politicians or bureaucrats – but it is a bad decision anyway."