
A passport is undeniably the most critical government-issued travel document. It serves as proof of identity and nationality worldwide and has a unique passport number, which allows authorities to verify whether the document belongs to the rightful holder.
This guide explains how passport numbers work and when they change.

While most national ID numbers stay the same throughout a person’s lifetime, passport numbers change every time a new one is issued.
Here are some of the instances when your passport number can change:
Renewal: every passport has an expiration date. Towards the end of its validity period, you need to renew it. Upon renewal, you’ll be issued a completely new document with a unique passport number.
Loss, theft or damage: if you lose your passport, you can request a replacement. The newly issued passport will have a fresh number to prevent any potential fraudulent uses of the old document. The same goes for if your passport is considerably damaged.
Upgrades or exceptional cases: many countries issue different types of passports, such as diplomatic, official, emergency etc., each with a new passport number, even if issued to the same person.
Change of name: if you legally change your name, you can renew your passport with the new details. The new passport you receive will have a unique passport number.

Yes. The passport number is assigned to the specific passport, not the person it belongs to. Therefore, when you renew your passport, the authority issuing the document will provide you with a new passport, which consequently will have a unique number.
To avoid any disruptions in your future travel plans, you can update your passport details wherever applicable – for example, airlines you frequently fly with or organisations or portals that require your passport details for identification, travel purposes etc.

No. You can’t travel internationally with an expired passport. Most countries require your passport to be valid for at least six months before your intended return date. It’s always better to renew your passport well before any foreign trips to avoid any last-minute hassles.
You will need your old passport if it contains an active visa for the destination you’re visiting. For instance, say you’re travelling to London, and your UK visa is in your expired passport. You’ll need to carry your old passport, which has the valid visa, as well as your newly issued passport.
Yes. You can book a flight even if your passport is still in the process of renewal. However, you should ensure the new passport is ready before your date of travel.
Yes. It’s possible to change your passport number after booking a flight. Most airlines will ask you to add your passport details at the time of booking. Depending on the airline, you can book a flight using your old passport details and update them once you get your new passport. You may also be able to update your passport number at the time of check-in. Make sure you also update any visa or immigration documents once you receive your new passport.
If your passport isn’t nearing its expiration date, you don’t need to apply for a new one unless it’s stolen, lost or damaged. However, if you’ve changed your name or other personal details, you may need to apply for a new passport reflecting the updated information. Another scenario where you’ll need a new passport is when you’ve run out of pages in your passport and don’t have sufficient space for visas and stamps.