Understanding ID Document Authentication: Process, Tools, and Challenges

There is no single definition of document authentication. It can vary depending on the context. That’s why it’s helpful to begin with the core concept. 

Authentication is the process of confirming that something is genuine and complete. In digital environments, it also proves that the user or device is authorized to access certain resources. Typically, authentication requires a known reference or sample for comparison. 

In the case of identity documents, authentication means verifying that the ID is both valid (not expired) and genuine (not altered or forged). It’s important to note that authentication isn’t about identifying what the document is, but about confirming its authenticity against a known reference.  

For example, when a border control officer receives a passport, they already know it is a passport, not a driver’s license or a residence permit. Their task is to confirm that the passport is:

• Authentic—issued by an official authority.

• Valid—not expired now or during the entire travel/stay period.

• Unaltered—containing only legitimate personal data and security features, just as it did on the day of issuance.

This task is easier with common documents that the officer sees regularly. But when presented with something less familiar—say, one of the world’s rarest passports—the process becomes more complex. Before authentication can begin, the officer must first identify the document.

In many cases, ID document authentication is a legal requirement, either mandated by law or outlined in industry guidelines. For instance, all air passengers must present a government-issued ID for authentication, following international rules established by ICAO to facilitate passport inspections, immigration control, and customs clearance. 

On a practical level, document authentication helps address the following tasks:

Document authentication helps detect impersonators using someone else's ID, as well as fraudsters with counterfeited or altered documents.

Any ID serves as proof of identity for its holder. That’s why face matching—comparing the photo in the document to the person presenting it—is always part of the process. During in-person checks, such as those conducted by police or border officers, the individual’s height or eye color may also be compared to the information in the document. Officers may even ask questions based on the data shown, such as the address. Remote scenarios involve authenticity checks with biometric verification as a mandatory step.

Document authentication enhances security in remote onboarding. The very presence of this check helps deter identity theft and limits fraudulent sign-ups, leading to fewer suspicious users. 

It also plays a critical role in access control, where an ID is used to verify someone’s right to enter restricted areas or facilities.

Regulated industries, such as banking, finance, and telecom, are required to authenticate IDs before providing services like opening an account or issuing a SIM card. These obligations fall under Know Your Customer (KYC) and Anti-Money Laundering (AML) regulations, which aim to prevent fraud, illegal money transactions, and terrorism financing.

Although KYC processes vary depending on a customer’s risk profile, ID document authentication remains a core element. Companies that fail to comply fully may face heavy fines or legal action.

Age checks are a key part of document authentication for businesses that sell age-restricted services or goods such as alcohol, tobacco, or pharmaceuticals. Since most IDs include a date of birth, this can be used to confirm the customer’s age. Some systems also use photo-based age estimation, which is a common feature in most identity documents.

It always depends on the specific use case. Typically, identity documents fall into three main categories:

Defined initially by the ICAO, this term is most commonly associated with passports. These IDs are usually issued following international standards and are recognized globally as proof of identity.

In addition to passports, driver’s licenses and ID cards can also serve as travel documents, though only in certain contexts. For example, EU residents can use their national ID cards and residence permits to travel within the Schengen zone and the European Economic Area (EEA)—however, certain restrictions apply, especially when traveling by air.

There are also rare forms of travel documents, such as emergency and diplomatic passports, seafarers’ identity documents, UN laissez-passers, and more.

This broader category includes all identity documents issued by government agencies. Some IDs specify the issuing authority directly. 

While issuing bodies differ by country, there are common patterns. For example, driver’s licenses are usually issued by transport authorities, while passport services often fall under ministries of foreign affairs.

In Argentina, however, passports are issued by the Registro Nacional de las Personas (RENAPER), the agency responsible for registering and managing citizens’ identification data.

Other identity documents may be issued by health, tax, or postal authorities. Even non-profit organizations can issue valid forms of ID. For example, the British CitizenCard is widely accepted for age verification in shops, pubs, and nightclubs within the country.

These IDs are typically valid only within the issuing country. A distinguishing feature is that they often use the country’s official language, whereas travel documents often include English, Spanish, or French as secondary languages. Also, domestic IDs may use local calendar systems that differ from the Gregorian calendar. Examples are Japanese and Thai documents.  

Domestic IDs include national identity cards and driver’s licenses. There are also many non-standard documents, which can have unique formats and purposes, some without a photo. Examples include voter cards, postal IDs (common in Asian countries like the Philippines and Sri Lanka), proof-of-age cards (e.g., in the UK and Denmark), tax cards, health insurance cards, and work permits.

Document authenticity verification includes several main stages, regardless of the document type. However, the sequence of actions may vary between in-person and remote scenarios, as well as across different use cases.

For example, according to identity check guidelines from the Norwegian police, an officer should first inspect the document for visible damage, then check the expiry date, name, and date of birth, followed by a comparison of all photos for resemblance. It’s also essential to verify that the document belongs to the person presenting it by comparing the photo with the face. Additionally, the officer may ask questions based on the document information, such as the date of birth.

Of course, this process looks different in other settings, such as hotels or casinos. At a hotel, a receptionist typically collects identification data for guest registration using their government-issued ID. At a casino, a guard will first check the visitor’s age and may also verify whether the individual appears on an exclusion list. 

To speed up on-site authentication of documents, police and border control officers often use specialized ID verification tools, including mobile document readers, manual inspection devices, magnifiers, and more. 

Businesses often rely on document readers that not only verify passports, ID cards, and driver’s licenses, but also offer helpful features like automated data entry.  

In remote scenarios, document authentication software is essential. Embedded into a website or mobile app, it performs automated checks after a user scans—or more accurately, takes a photo of—their ID.

Let’s take a closer look at the key stages of the process using a remote scenario as an example:

First, the system captures an image of the ID—in most cases, the data page containing all identification information and the holder’s portrait. However, not just any photo will be acceptable. There are specific requirements the image must meet: it should be well-lit, properly framed, and in focus, with no blur or cropped sections. 

In some cases, the capture process involves recording a short video while the ID is tilted in front of the camera. This enables additional checks, such as liveness detection.   

Regula Document Reader SDK allows customization of the capture stage to enhance user experience and accessibility. It also features advanced document capture and image quality assessment to help get the perfect shot on the first try.

Next, the software identifies the document type—passport, driver’s license, visa, etc.—and detects key attributes that need to be verified. These can include the machine-readable zone (MRZ)—which is required for travel documents but sometimes absent in domestic IDs—barcodes, electronic chips embedded into biometric documents, and other security features.

Once the document is recognized, the system extracts all necessary data for identification and verification. This includes personal details in the visual inspection zone (VIZ), as well as machine-readable data from the MRZ, barcodes, and e-chip.

This step relies on Optical Character Recognition (OCR) technology, which reads the text in the image and converts it into a digital format. The software uses its ID template library to apply the correct layout and ensure accurate extraction. 

With all the data extracted and standardized, the software moves to the final step—verification. This includes both standard and advanced checks. 

Standard checks involve cross-verifying information across the VIZ, MRZ, barcode, and chip to ensure data consistency and integrity. 

Advanced checks may include document liveness detection, which verifies that a physical document is being presented, not a printout, screenshot, or AI-generated image. 

For biometric documents, server-side verification may be used to validate the results initially obtained by the user’s mobile device. 

If everything checks out, the document is confirmed as valid and authentic.

In theory, ID document authentication requires only two things:

1. A clear understanding of what a genuine ID should look like (a reference).

2. A checklist of what should be verified (a procedure). 

Hardware and software tools help streamline the process through smart automation. 

But in practice, it’s rarely that simple.

The real world is full of different identity documents, which makes authenticating documents a true challenge. 

First, many IDs, especially domestic ones, don’t follow international standards when it comes to layout, design, data sets, or even the quality of security features. As a result, even commonly used elements like the MRZ can be difficult to verify. What’s more, countries regularly update their passports, driver’s licenses, and ID cards, which means multiple versions of the same document may be in circulation at once. 

Second, this variety creates a challenge for maintaining a complete and up-to-date reference database. It’s a problem not only for border control officers but also for businesses conducting remote document authentication. With global travel and migration on the rise, it’s increasingly likely that organizations will need to verify less familiar or “non-typical” documents.

That’s where document template databases come into play. They’re essential to the authentication process, providing a verified reference sample that shows the correct layout, data fields, security features, and more. For instance, Regula currently maintains two databases: the Information Reference Systems, which are digital catalogs containing high-quality images of travel and vehicle documents, and the Regula Document Reader SDK database, which includes over 15,000 document templates from 252 countries and territories.

ID diversity creates opportunities for fraudsters, who continue to find ways to bypass document authentication. 

In remote scenarios, traditional methods such as photo or data page substitution are now being combined with more advanced tactics. The rise of deepfake technology, for example, has enabled attackers to create convincing fake IDs that mimic genuine document scans complete with natural lighting, realistic backgrounds, and other visual details. 

These threats require advanced technologies and proactive countermeasures from IDV solution providers, as well as greater expertise from inspectors.

This last challenge may not be obvious, but it’s becoming increasingly important. As more companies move their services online, document authentication is often handled through mobile apps, making it a crucial part of the user onboarding experience. 

Since onboarding is partly managed by marketing teams focused on metrics like churn or drop-off rates, there’s growing pressure to make document authentication smooth, fast, and user-friendly. A slow or confusing process can lead to repeated ID scans or user abandonment.

To meet these expectations, organizations need customizable solutions that offer flexibility in everything from localization to interface design.

With over 30 years of experience in forensic research and the world’s largest library of document templates, Regula develops cutting-edge technologies for document and biometric verification. 

Our toolkit includes a wide range of hardware devices for accurate document authentication, as well as specialized software—Regula Document Reader SDK—which is cross-platform and fully customizable. 

Don’t hesitate to book a call with one of our representatives. We’ll help you find the best solution for your needs.