# Strong Customer Authentication & 2FA

Strong customer authentication (SCA) is a security measure that requires customers to provide multiple forms of identification to verify their identity before accessing sensitive information or performing high-risk transactions.

The goal of SCA is to prevent fraud and protect sensitive information by ensuring that only authorized users can access it.

You can think of SCA as a form of multi-factor authentication (MFA) designed specifically for financial services. However, MFA is a broader technical concept while SCA defines the business feature.

## European regulatory requirement

SCA is a European regulatory requirement as part of the second
[Payment Services Directive (PSD2)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32015L2366) for authenticating online payments and making them more secure.

Some actions require SCA in the UK and EEA, such as funding a transfer from your multi-currency account or retrieving a statement.

Please note that Wise may enforce SCA on endpoints based on our risk assessment as part of our best efforts for consumer protection.

## SCA-protected endpoints

At Wise, when an endpoint performs an action that requires strong customer authentication, the initial request to that endpoint is rejected with a response status of `403 (Forbidden)` to inform you that stronger authentication is needed. The endpoint can be retried again with stronger authentication.

When an endpoint requires a stronger authentication, we've indicated so by adding an alert banner like ths to the endpoint reference:

For more information on how to build a stronger authentication request call, review our [One Time Token guide](/guides/developer/auth-and-security/one-time-token).

## Connection guide

How you implement SCA will depend on your [integration method](/guides/product/send-money/transfers).

For details on how to implement SCA for your integration, select the recommended SCA guide that corresponds to your integration method from the following list.

| Integration method | Recommended SCA guide |
|  --- | --- |
| [Embedded finance using partner KYC](/guides/product/kyc/partner-kyc) | [SCA over API](/guides/developer/auth-and-security/sca-over-api) |
| [Embedded finance using Wise KYC](/guides/product/kyc/wise-kyc) | [Embedded SCA component](/guides/developer/auth-and-security/embedded-sca-component) |
| [Correspondent or Enterprise partner accounts](/guides/product/kyc/partner-accounts) | Contact our [sales team](https://wise.com/gb/business/contact#contact) |
| [Open banking](/guides/developer/open-banking) | [Open banking guide](/guides/developer/open-banking) |


If you are unsure of your integration method, contact our [support team](/guides/product/partner) to advise on the most appropriate solution for your use case.