Most passports issued in the past decade or so are biometric — they contain a small electronic chip that stores the holder's personal data and photograph. Biometric passports have become a fundamental part of modern border control, and some countries now require them for visa-free access or eVisa eligibility. Here is what the chip actually contains, how automated gates work, and why your passport's chip status may matter more than you expect.
What makes a passport "biometric"?
A biometric passport — often called an e-passport — contains a small RFID (radio-frequency identification) chip embedded in the cover or data page. The chip stores a digital version of the information printed on the passport's biographical data page: your name, date of birth, nationality, and the photograph used on the photo page.
In many countries, the chip also stores at least one additional biometric identifier: a digital facial image (used in facial recognition gates), and sometimes fingerprints. The specific data stored depends on what the issuing country chose to include when the passport was produced.
The characteristic symbol on the cover — a small rectangle with a circle above a horizontal line, representing a chip and antenna — indicates that a passport contains a chip. If you are unsure whether your passport is biometric, check its cover for this symbol or look at the issue date: most countries completed their rollout of biometric passports in the late 2000s or early 2010s, though some issued them as early as 2005–2006.
Why biometric passports were introduced
The shift to biometric passports was driven by two main concerns: security and identity verification. Traditional printed passports could be counterfeited or altered, and even well-made modern security features could not fully eliminate fraud. A chip that stores cryptographically signed data that must match the printed information adds a layer of verification that is very difficult to fake without access to the issuing country's digital signing key.
The International Civil Aviation Organisation (ICAO) — the United Nations body that sets global standards for civil aviation and travel documents — published the standards for biometric passports (known as Machine Readable Travel Documents, or MRTDs) that countries have adopted. This standardisation is what allows border authorities around the world to read passports from many different countries with the same equipment.
What the chip stores
The chip in an ICAO-compliant biometric passport contains several data groups. The mandatory ones include:
- Machine-readable zone (MRZ) data: the same information in the two lines of text at the bottom of your photo page — name, document number, nationality, date of birth, expiry date.
- Facial image: a standardised digital photograph, suitable for use in facial recognition.
- Document security data: a digital signature from the issuing country's certificate authority, so that readers can verify the chip data has not been altered.
Optional additions (implemented by some but not all countries) include fingerprints and, in a small number of cases, iris scans. Whether these are stored depends on the issuing country's policy. UK passports, for example, store fingerprints from certain issue dates; US passports store only the facial image on the chip.
The chip does not store your address, your travel history, your bank details, or any other personal information beyond what is on the printed page. This is a common misconception — the chip essentially provides a tamper-resistant digital copy of what is already visible in the passport.
How border gates read your passport
Automated border control gates — the self-service lanes increasingly found at major airports — work by combining several checks:
- Your passport is placed on or scanned by a reader. The machine reads the MRZ strip optically, which provides a key to communicate with the chip.
- Using that key, the gate establishes a secure connection with the chip (via the Basic Access Control or PACE protocol) and reads the stored data.
- The digital signature is verified against a database of issuing country certificates, confirming the chip data is authentic and unaltered.
- The facial image from the chip is compared to a live photograph taken by the gate's camera, verifying that the person presenting the passport is its legitimate holder.
If all checks pass, the gate opens. If any check fails — because the chip cannot be read, the signature is invalid, or the face does not match — the traveller is redirected to a staffed desk for manual checking.
Why some countries require biometric passports for entry
Several countries — notably the United States and Australia — require that visitors using visa-free entry (ESTA, ETA) must hold a biometric passport from an eligible country. Older passports without a chip do not qualify for these online travel authorisations, even if the nationality would otherwise be eligible.
This matters in practice: if you hold an older passport from an eligible country that happens not to be biometric — perhaps issued before your country's rollout was complete, or a valid but old emergency passport — you may be unable to obtain an ESTA or Australian ETA and would need to apply for a full visa instead. It is worth checking whether your current passport is biometric before applying for these authorisations.
For more on travel authorisations specifically, see our guides on the US ESTA and European ETIAS.
Chip failures and what to do
Passport chips can fail — typically from physical damage (bending, moisture, or heat) or simply reaching the end of their electronic life. A failed chip does not invalidate the passport itself, but it means you cannot use automated gates that require chip reading, and you may face additional scrutiny at some borders. If your passport has a failed chip, you will need to use staffed counters where an officer manually checks your document.
If you suspect your chip has failed (you can check with an NFC-enabled smartphone and a passport reader app), consider applying for a new passport before travelling, particularly if you plan to use a US ESTA or Australian ETA that requires a functioning chip. Reporting a chip failure to your passport issuing authority may be advisable depending on your country's policies.
Protecting your passport chip from skimming
The chip uses RFID technology, which has prompted concerns about whether someone could read your passport data from a short distance without your knowledge. In practice, the ICAO security protocols — particularly Basic Access Control — mean that the chip cannot be read without first optically scanning the MRZ, which requires the passport to be physically open. This largely defeats the theoretical skimming risk for compliant readers.
RFID-blocking passport covers and wallets are widely sold. Whether you feel they add useful protection is a personal judgement; the technical risk of contactless skimming for modern biometric passports is considered low by security researchers. The bigger security risk is losing your passport altogether — keeping it in a secure inside pocket or locked luggage is more likely to protect you in practice.
For more on travelling with important documents, see our guide on passport validity rules and what different countries require.
Frequently asked questions
How do I know if my passport is biometric?
Look for the small gold symbol on the front cover of your passport — a rectangle with a circle and horizontal lines, representing a chip. If that symbol is present, the passport contains a chip and is biometric. You can also check the issue date: most countries completed their biometric rollout by around 2010–2012, so a passport issued after that date from a major country is almost certainly biometric.
Does a biometric passport mean my fingerprints are stored?
Not necessarily. Whether fingerprints are stored on the chip depends on the issuing country. All biometric passports store a digital facial image; many (but not all) also store fingerprints. The US passport currently stores only the facial image. UK passports store fingerprints from a certain issue date. Check your issuing authority's guidance if you are unsure.
Can I use automated e-gates at airports with any biometric passport?
Not always. Automated gates at any given airport are typically set up to accept specific nationalities. British citizens in the UK, EU citizens at EU airports, and other combinations have different access rules. Some airports allow a wider range of nationalities to use e-gates; this is a matter of the operating authority's policy, not just whether your passport has a chip.
What if my biometric passport chip stops working?
The passport remains valid as a travel document even if the chip fails. However, you will not be able to use automated e-gates that rely on chip reading, and you may face additional checks at some borders. You can continue to travel using staffed passport control. If you rely on US ESTA or similar systems that require a readable chip, consider applying for a new passport.
Sources and further reading:
- International Civil Aviation Organisation (ICAO) — sets global standards for biometric travel documents (Doc 9303).
- Your country's passport issuing authority for specific chip content and rollout dates.
- European Commission — information on e-gate access arrangements for Schengen entry.
- IATA — information on travel document requirements by route.