# Valid phone numbers for SCA
For optimal performance of Secure Contacts App (SCA), particularly for **incoming caller identification**, it is important that stored phone numbers are in the correct international format. Proper formatting ensures accurate recognition across regions and systems, avoiding errors in caller identification.
### International Phone Number Format
SCA uses the **ITU-T E.164 international standard** to normalize and verify phone numbers. This format ensures each number is globally unique and correctly routed for calls.
**Key features of E.164 format**:
* Starts with a plus sign (`+`)
* Includes the country code
* Contains the subscriber number, including area code if applicable
**Examples**:
* Local format: `020 7946 0958` (UK)
* E.164 format: `+442079460958`
{% hint style="success" %}
Phone numbers that cannot be automatically completed into a valid international format are considered invalid. In this case, depending on the current location, the number may still be used for outgoing calls, but **will not be recognized for identifying incoming callers**.
{% endhint %}
### Optional Configuration Parameters
SCA provides optional parameters to help handle numbers that are not in the correct format:
* [**PhoneNumberParseCountryCode\_Option**](https://docs.secure-contacts.com/app-configuration-policy-name-values-for-sca/sca-configuration-seccontacts.defaults#appearance-and-functions): Defines a 2-letter country code (e.g., `DE` or `US`) to automatically format numbers without a country code.
* **Default**: `false` (no default country code applied)
* [**PhoneNumberIngoreInvalid\_Option**](https://docs.secure-contacts.com/app-configuration-policy-name-values-for-sca/sca-configuration-seccontacts.defaults#appearance-and-functions): Filters out numbers that cannot be normalized to E.164 format, ensuring only valid numbers are processed for caller identification.
* **Default**: `false` (invalid numbers are not filtered by default)
These parameters can **mitigate issues** with incorrectly stored numbers but using the correct format from the start is always recommended.
{% hint style="info" %}
Instructions on how to apply SCA **App Configuration** settings are available [here](https://docs.secure-contacts.com/documentation/app-configuration-policy-name-values-for-sca/sca-configuration-seccontacts.defaults)
{% endhint %}
### Examples of valid international phone numbers:
| phone numbers in data source | SCA parsed & formated | is valid |
|---|
| +49 69 3531247 | +49 69 3531247 | yes |
| +49 (0)89 56164193 | +49 89 56164193 | yes |
| 004930124711372 | +49 30 124711372 | yes |
| +1 (415) 555-2332 | +1 415-555-2332 | yes |
| 001 646 940 8602 | +1 646-940-8602 | yes |
| 001-410-555-1331 | +1 410-555-1331 | yes |
| +34 91 426-0693 | +34 914 26 06 93 | yes |
| +34608246176 | +34 608 24 61 76 | yes |
| 14045551337 | +1 404-555-1337 | yes |
| 491734532510 | +49 173 4532510 | yes |
### Examples of invalid phone numbers:
| phone numbers in data source | SCA parsed & formated | is valid |
|---|
| (415) 555-2332 | (415) 555-2332 | no |
| 410 555-1331 | 410 555-1331 | no |
| 914260693 | 914260693 | no |
| (0)89 56164193 | (0)89 56164193 | no |
| 01725570802 | 01725570802 | no |
| 313-433-723 | 313-433-723 | no |
| 7321-334 | 7321-334 | no |
| 2001 | 2001 | no |
### Integration with Data Sources
SCA integrates with various data sources such as **AAD, GAL, APC, D365, DVRS, ABS, and SMC**. To maintain consistent caller identification, phone numbers in these sources should also follow the international format.
### Summary
* Correctly formatted phone numbers are critical for reliable incoming caller identification.
* SCA normalizes and validates numbers according to ITU-T E.164 standards.
* Optional parameters help handle improperly formatted numbers but do not replace storing numbers correctly.
* Consistency across integrated data sources ensures accurate recognition and seamless functionality.