> ## Documentation Index
> Fetch the complete documentation index at: https://docs.go.gbgplc.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Biometric verification
> Invite a customer to a No-code journey that verifies them biometrically.
This guide shows you how to confirm that the customer presenting an identity document is the person shown on it. You build a Hosted journey from three document modules and a facematch module, invite one customer by email or text message, and then review the result in Investigation. You **don't** write any code or call the API.
By the end of this guide, you can see whether your customer's selfie matches the portrait on their document. You can also see the decision that the GBG Go platform reached.
The **Invite a customer** action is only available for published Hosted journeys. If your journey collects information before it starts, then the action is unavailable. See [When the invite action is unavailable](/docs/go-v2/get-started/quickstart/quickstart-invite-a-customer#when-the-invite-action-is-unavailable).
## Before you begin
Ensure you have the following:
* A GBG Go platform account with a customer admin role. This role lets you review the result in Investigation. If you don't have this role, then contact your GBG account manager.
* The Document Classification, Document Extraction, Document Authentication, and Facematch Verification modules enabled in your contract.
* A licence and credentials for the User Invite module set up for your organisation.
* An identity document that carries a portrait photograph, such as a passport or driving licence.
* An email address or mobile number that you can receive the invite on, so that you can complete the journey as your customer.
## Why the journey needs document modules
Facematch compares two images. The first is the selfie your customer takes during the journey. The second is the anchor image, which is the portrait photograph taken from their identity document.
The Document Classification module produces the anchor image. It identifies the document and extracts the portrait from it, so facematch has something to compare the selfie against. Without a document module ahead of it, facematch has no anchor image and can't run.
This is why the journey verifies a document first and matches the face second.
| Order | Module | What it does |
| ----- | --------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| 1 | **Document Classification** | Identifies what the document is and which country issued it. It also produces the anchor image that facematch compares against. |
| 2 | **Document Extraction** | Reads the data from the document, such as the name, date of birth, and expiry date. |
| 3 | **Document Authentication** | Checks whether the document is genuine and shows no signs of tampering. |
| 4 | **Facematch Verification** | Compares your customer's selfie against the anchor image, and reports whether the two faces belong to the same person. |
This guide uses the V2 variants of the three document modules. The V1 variants of these modules are not available in v2. See [V1 to v2 migration guide](/docs/go-v2/migration/v1-to-v2-migration-guide).
## Step 1: Create a Hosted journey
1. Click on the **Create a new journey** list.
2. Select **API + hosted (latest)**. This opens the Journey builder, allowing you to design Hosted journey workflows.
3. Click the edit icon on the journey name at the top of the editor.
4. Enter a meaningful name, for example, "Biometric Verification - New Customers."
5. Click outside the name field to save it.
## Step 2: Add the document modules
Add the three document modules in order. You select a variant as part of adding each module. These are the same three modules, in the same order, as the [Identity document verification](/docs/go-v2/low-code-builder/no-code/guides/identity-document-verification) guide.
1. Go to **Browse and add modules** in the right sidebar.
2. Use the search bar to find **Document Classification**.
3. Click the module. This opens the module configuration panel, which lists the available variants.
4. Select the **Document Classification V2** variant.
5. Click **Add to journey** to insert the module into the flow.
6. Repeat steps 1 to 5 for the remaining two modules, in this order:
| Module | Variant |
| --------------------------- | -------------------------- |
| **Document Extraction** | Document Extraction V2 |
| **Document Authentication** | Document Authentication V2 |
## Step 3: Select a facematch variant
You select a variant as part of adding the module. Both variants compare the same two images, but they report the result differently.
1. Go to **Browse and add modules** in the right sidebar.
2. Use the search bar to find **Facematch Verification**.
3. Click the module. This opens the module configuration panel, which lists the available variants.
4. Select one of the following variants:
| Variant | What it does |
| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Facematch Verification - NIST** | Returns a match or no-match result. It uses an algorithm independently evaluated under the NIST Face Recognition Vendor Test programme. Recommended for this guide. |
| **Facematch Verification V2** | Returns a similarity score from 0 to 100. You set the thresholds that decide when a score is accepted. |
5. Click **Add to journey** to insert the module into the flow.
This guide uses **Facematch Verification - NIST**. It reaches a definitive result on your behalf, so you can review a clear match or no-match outcome without configuring thresholds first.
Your journey now runs classification, extraction, and authentication, and then compares the face, as shown in the previous image.
Modules and variants marked with an orange warning icon require activation by the GBG team. If a variant you need is marked, then contact your account manager to enable it for your organisation.
To compare the variants in detail, see [Facematch Verification](/docs/go-v2/platform/modules/biometrics/facematch-verification).
## Step 4: Review the facematch outcomes
The module arrives pre-configured with default outcomes, so you don't need to configure anything before you publish.
To review the outcomes:
1. Click the **Facematch Verification** module inside the Journey builder to open its configuration panel.
2. Click **Configure outcomes**. The outcomes and their rules appear.
3. Review the following outcomes:
| Outcome | Condition | Description |
| --------- | ----------------------------------- | -------------------------------------------------------------------------------------------- |
| `Success` | The facematch result is `Match`. | The selfie matches the document portrait. Your customer is confirmed as the document holder. |
| `Fail` | The facematch result is `No Match`. | The selfie doesn't match the document portrait. |
| `ERROR` | No condition matched. | The facematch check couldn't be completed. |
4. Click **Close** to apply your configuration.
**Facematch Verification - NIST** also returns a similarity score from 0 to 100. A score above 50 produces a `Match`, and a score of 50 or below produces a `No Match`.
A `No Match` result doesn't always mean your customer isn't the document holder. A poor-quality document portrait produces the same result. Route a `No Match` to a manual review rather than to an automatic rejection, so that a reviewer can compare the two images.
To route each outcome to a different path, add an Evaluation node to your journey. To learn more, see [Set up evaluation](/docs/go-v2/platform/journey-builder/set-up-evaluation) and [How to configure module outcomes in Go](/docs/go-v2/guides/product-guides/configure-outcome-decisions).
## Step 5: Publish the journey
Click **Publish to Preview** in the Journey builder. GBG Go displays a confirmation message.
Next, click **Dashboard** to see:
* Environment (Preview)
* Version number
* Resource ID
* Last published
* Actions list
Your journey is now available for testing in the preview environment.
## Step 6: Invite your customer
1. Click the **Actions** list.
2. Click **Invite a customer**. A dialog box appears.
3. Select the options for your use case, and then enter an email address, a mobile number, or both. The dialog box contains the following options:
| Option | Description |
| --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Region** | The region that the journey runs in. Select **EU**, **US**, or **AU**. Your organisation may only be set up in some regions. |
| **Environment** | The environment that the journey runs in. Select **Production** or **Preview**. If you can't select an environment, then the journey isn't published there yet. |
| **Send invite to** | Enter an email address, a mobile number, or both. |
| **Advanced settings** | The link expiry and session behaviour that the invite uses. Expand this to review the current values, which come from the [link settings](/docs/go-v2/platform/link-settings) on the journey. |
The GBG Go platform presets the region and environment based on the journey that you selected. Select **Preview** while you test the journey. Change the region only if your organisation runs journeys in more than one region, because the region controls where your customer's data is processed and stored.
4. Click **Invite**. A message appears at the top right of the screen confirming that the invite started.
An invite is valid for one customer. By default it expires after seven days, and your customer can return to the journey if they close it before they finish. To change either default, see [Link settings](/docs/go-v2/platform/link-settings).
## Step 7: Complete the journey as your customer
Your customer receives a verification link by email or text message.
1. Open the link from the invite.
2. Photograph your identity document when the journey asks for it. Capture both sides if the document is double-sided.
3. Take a selfie when the journey asks for it.
4. Submit the images.
Watch this demo to see the journey as your customer experiences it.
The GBG Go platform classifies the document, extracts its data, and checks whether it is genuine. It then compares your selfie against the portrait taken from the document.
Capture the selfie in even, front-on light, with your whole face visible and nothing covering it. Remove sunglasses and hats. Facial hair, glasses, and a significant age gap between the document photograph and the selfie can all lower the similarity score without any fraud being involved.
## Step 8: Review the verification result
Results are available in Investigation once your customer completes the journey.
1. Click **Investigation** on the left navigation menu. The Investigation dashboard opens.
2. Select the environment that you sent the invite to. If you are testing, then click the **Preview Environment** tab.
3. Select the region that you sent the invite to, using the region list in the top-right corner.
4. Find your customer's session in the list. If the list is long, then click **Add Filter** to search by name or email address.
5. Click the session ID. The session details page opens on the **Processing** tab.
6. Find the Facematch Verification module in the list. The outcome appears on the right of the module name, for example, **Success**.
7. Click the arrow on the module row to expand it. The module shows the rule it evaluated, and whether that rule returned true or false. A **Facematch Result** of `Match` returning **True** means the selfie matched the anchor image that Document Classification supplied.
8. Click **More details** to drill into the module on its own page. Review the facematch detail on the following tabs:
| Tab | What it shows |
| ----------------- | ---------------------------------------------------------- |
| **Score** | The similarity score for the comparison. |
| **Results** | The module results and the rule that produced the outcome. |
| **Raw Response** | The full response that the facematch service returned. |
| **Outcome Rules** | The rules that produced the outcome. |
You have now confirmed that your customer is the person shown on their identity document, and reviewed the result.
Review the document modules alongside the facematch result. A facematch that fails after a `Document NOT Classified` result usually points to a poor document photograph rather than a mismatched face, because a poorly captured document yields a poor anchor image.
## Next steps
* Change the decision on a session after your review: [Change decisions](/docs/go-v2/platform/investigate/change-decisions).
* See everything a session records: [View details of a journey session](/docs/go-v2/platform/investigate/view-journey-details).
* Understand the results the module returns: [Facematch Verification](/docs/go-v2/platform/modules/biometrics/facematch-verification).
* Confirm a live person is present before you match the face: [Liveness Verification](/docs/go-v2/platform/modules/biometrics/liveness-verification).
* Structure a journey that combines documents and biometrics: [How to combine document and biometric modules](/docs/go-v2/guides/best-practices/docs-and-bio).
* Invite a customer to a journey built for another verification task: [No-code guides](/docs/go-v2/low-code-builder/no-code/overview#guides).