People with new passports should make sure to sign theirs before jetting away - or they could be stopped from travelling.
The UK Government's HM Passport Office requires everyone to put their signature on the document with a specific pen under rules for blue passports.
Every blue passport holder is being warned to sign the document with a specific type of pen, otherwise it could be deemed invalid.
The new blue passports have replaced old red ones, with millions being issued the new document since Brexit.
However, a signature must be completed with a black ballpoint pen.
The Government website states: "Sign your new passport as soon as you get it. You can’t use it until you do.
"Sign on the ‘holder’s signature’ line using black ballpoint pen."
HM Passport Office started to introduce passports that will no longer include the holder's signature in digital format, which was previously found on the photo ID page.
Instead the passport holder is required to sign their passport after it has been issued to them .
This is to be done on the line above the photo ID page.

Valid UK passports with the signature in digital format will continue to be in circulation up until around 2027.
The distinctive blue cover passport was introduced in March 2020 and will replace burgundy passports which were gradually rolled out from 1988.
It also includes the latest and most secure printing and design techniques, which means it offers better protection against identity theft and fraud and will be even harder to forge.
Those with valid, burgundy passports can continue to use their passport for travel until it expires.
When you don’t need to sign
You don’t need to sign your new passport if:
- you’re aged 11 or under
- you can’t sign because of a disability
The passport will show ‘the holder is not required to sign’ on the page with your name and photo on it.
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