How Does Fingerprinting Work?

Fingerprinting has become one of the most widely used methods for identity verification. Since every person has a different fingerprint pattern, it helps organisations confirm an individual’s identity accurately. From government checks to workplace screening, fingerprints play an important role in verifying personal information. This guide explains how fingerprinting works, how prints are processed, and why they are used.

Fingerprints are patterns formed by raised ridges of skin on the surface of the fingertips. These ridges create three broad pattern types:

Fingerprints begin forming during the third and fourth month of pregnancy. The middle layer of skin grows faster than the inner and outer layers, causing the surface to buckle into ridge formations. The exact shape of those ridges depends on physical conditions in the womb - foetal position, pressure, and the movement of amniotic fluid - none of which are the same for any two people. Even identical twins, who share the same DNA, develop different fingerprints because those physical conditions differ between them.

Once formed, the ridge pattern is fixed. It does not change with age. The ridges expand proportionally as a person grows, but the pattern remains the same. Skin damage, aging, or certain manual work can affect the surface clarity of prints, but the underlying structure stays intact.

Step 1 - Identity details are recorded

Before fingerprints are taken, the applicant's personal information is collected. This includes full name, date of birth, identification document details, and the purpose of the fingerprinting. This information is written directly onto the fingerprint card or entered into the digital system. It must match the identification documents exactly - any mismatch can cause delays or rejection.

Step 2 - Fingerprints are captured

There are two methods:

Ink fingerprinting: Each finger is pressed onto an ink pad and rolled firmly onto a fingerprint card - an FD-258 card for FBI submissions, a C216-C card for Canadian RCMP submissions from outside Canada, or the card format required by another authority. Each finger is rolled from nail edge to nail edge to capture the full ridge width. The ink transfers the ridge pattern directly onto the card surface.

Digital fingerprinting (live scan): The finger is placed on an electronic scanner. A sensor reads the ridge pattern and converts it into a digital image, then into a mathematical template stored as a file. No ink is used. The quality of each print can be checked on screen during the session, which means poor prints are retaken immediately rather than discovered after submission.

Step 3 - Quality is checked

After capture, every print is reviewed. Clear ridge detail, complete impressions, correct finger placement, and no smudging are required. If any print does not meet the standard, that finger is recaptured before the appointment ends. A trained technician reviews the full card before it leaves the session - this step catches most errors before they become resubmissions.

Once submitted, fingerprints are compared against stored records using an Automated Fingerprint Identification System (AFIS), or reviewed directly by a fingerprint examiner.

The system does not match the overall shape of the pattern. It looks for specific ridge details called minutiae points -the exact locations where ridges end abruptly, where a single ridge splits into two branches, or where short isolated ridges appear. A human fingertip contains between 75 and 175 of these points. The system compares the submitted print against stored records and identifies whether enough minutiae points align in the same positions to confirm a match.

For checks such as an FBI Identity History Summary or an RCMP criminal record check, the system searches the relevant database and returns any matching records. Fingerprints are more reliable than name-based searches because names can be shared, changed, or misspelled. A fingerprint match is specific to one person.

Digital fingerprinting uses different sensor technologies depending on where the system is used:

• Optical scanners use a light source and camera to photograph the fingertip surface. Ridges and valleys reflect light differently, producing a clear image of the pattern. These are the most common scanners in law enforcement offices and professional fingerprinting services.
• Capacitive scanners measure the electrical difference between the raised ridges, which touch the sensor surface, and the lower valleys, which do not. This produces a map of the ridge pattern without light. Capacitive sensors are used in most smartphones and building access systems.
• Ultrasonic scanners use high-frequency sound waves to map the fingerprint surface, including depth beneath the skin. They work through moisture, minor skin damage, and surface contamination that would affect optical or capacitive sensors. Ultrasonic scanners are found in newer mobile devices and some high-security systems.

All three scanner types convert the captured image into a digital template - a mathematical representation of the minutiae points - which is stored and used for comparison. The raw fingerprint image is not what gets stored or compared in most systems.

• Background Checks: Fingerprints are used to verify a person’s criminal record history through government databases, such as FBI or RCMP checks.
• Immigration and Visas: Many countries use fingerprints to confirm identity and complete security checks for visas, residency, and citizenship applications.
• Employment Screening: Employers in healthcare, education, finance, and government roles use fingerprint checks to verify applicants before hiring.
• Security Clearances: Government and defence organisations use fingerprints to confirm identity for sensitive positions.

Names, dates of birth, and identity numbers can be shared, changed, or duplicated. A fingerprint is biologically unique to one person and cannot be transferred.

This matters most in large-scale identity checks. When a database holds records for millions of people with similar names or birth dates, a name-based search produces multiple possible matches that must be reviewed manually. A fingerprint search returns only records that match the specific minutiae pattern submitted.

Fingerprints also provide continuity across name changes, document renewals, and jurisdictional borders. A person who has changed their name, used multiple identity documents, or moved between countries can still be matched to their fingerprint records - provided those prints were captured and submitted to the relevant database at some point.

Applicants based outside the country they are applying to face additional steps that domestic applicants do not. The fingerprint card must meet the receiving authority's approved format, be sent internationally, and returned the same way. Each stage adds time to the total, and any error at the capture stage means the entire process restarts from the beginning.

Shipping documents across borders introduces delays that are outside the applicant's control. Building buffer time into the schedule before any visa, employment, or licensing deadline is essential.

Common challenges international applicants face:

• Sourcing the correct approved fingerprint card format in their country.
• Finding a local fingerprinting provider familiar with foreign authority requirements.
• Managing international courier timelines in both directions.
• Customs clearance delays holding documents longer than expected.
• Restarting the full process if prints are rejected after international delivery.

Using an approved channeler, where the receiving authority permits it, reduces the timeline significantly. Channelers submit fingerprints electronically on the applicant's behalf rather than by physical mail, which removes the longest wait in the process. Not all authorities accept channeler submissions from international applicants, so confirming the available options before applying is worth doing.

For applicants in regional or remote areas who cannot reach a fingerprinting provider, mobile fingerprinting services travel to the applicant's location with all required equipment and the correct card formats for the submission destination.

Key requirements for any international fingerprint submission:

• Use the correct approved card format specified by the receiving authority.
• Complete every personal information field accurately - no blank fields.
• Match all names and dates exactly to your identification documents.
• Send documents flat in a rigid envelope to avoid damage in transit.
• Use a tracked international courier - untracked mail creates no delivery record and cannot be followed up if lost.
• Keep copies of all documents before sending the originals.

Before the appointment: Bring valid photo identification and any forms the requesting organisation requires. Keep your hands clean and dry. Avoid using heavy hand creams immediately before the appointment, as they can affect ink adhesion.

• During the appointment: The technician verifies your identity using your identification documents. Your fingerprints are captured finger by finger, with each one rolled from side to side. The technician checks each print for quality before moving on.
• After the appointment: The completed fingerprint card or digital file is submitted to the relevant authority. Processing time depends on the organisation receiving the prints and the type of check being conducted.

Most fingerprinting appointments take 15 to 30 minutes.

Mobile fingerprinting is a service where a trained technician travels to the applicant's location - home, workplace, or another agreed site. The technician brings the required equipment and fingerprint cards.

This option is useful for applicants in regional or remote areas, people who cannot travel easily, and businesses or groups needing multiple people fingerprinted at the same time. The process and quality standards are the same as a fixed-location appointment.

Globeia offers professional fingerprinting services across the UK, Australia, India, Spain, Portugal, Germany, France, Switzerland, and other European countries, including regional areas, through trained mobile fingerprinting technicians.

Services support FBI and RCMP fingerprint submissions using the correct fingerprint card formats required by each authority. Every fingerprint set is carefully reviewed for quality before submission to help reduce the risk of rejection.

Globeia also supports the complete Criminal Record Check process, including application assistance, SmartPortal tracking, and apostille services for the USA, UK, and Canada when required.

Fingerprinting works by capturing the unique ridge patterns on a person's fingertips and comparing them against stored records to confirm identity. The process is accurate, consistent, and accepted by governments and organisations worldwide.

Clear prints, the correct card format, and complete personal details are what determine whether a submission is accepted or returned. Using a trained professional removes most of the risk from the process.