# FAQs (/global/en/docs/Terminal/P2PE-Security-Empowerment-SDK/P2PE-Application-PaymentLink/FAQs)

These Technical Frequently Asked Questions (Tech FAQs) provide answers to questions regarding the PaymentLink Security Requirement and Testing Procedures, including the associated Program.

These FAQs are designed to assist developers, security professionals, and assessors in better understanding and implementing the PaymentLink security standards.

**"Q1: What is the relationship between PaymentLink and NSDK/EMVL3/PaymentService?"**

NSDK, EMVL3, and PaymentService provide comprehensive application interfaces through their respective SDKs to deliver original functionalities.

PaymentLink is an SDK component developed on top of NSDK, EMVL3, and PaymentService, designed to meet P2PE requirements. It includes security modules and card reader modules from NSDK, full EMVL3 functionality, complete PaymentService features, and adds necessary P2PE module functionalities.

**"Q2: Is it still necessary to use the SDKs of NSDK/EMVL3/PaymentService when using PaymentLink?"**

When using the PaymentLink SDK, there's no need to use the SDKs of EMVL3 and PaymentService anymore.

However, you still need to use the core package of NSDK as a dependency definition.

**"Q3: What is the permission control scheme when mixing PaymentLink with NSDK?"**

When using PaymentLink, ensure that the application is designated as a "No Payment" app, avoiding direct calls to security and card reading interfaces within NSDK. Strictly control application permissions.

For using basic functionalities such as beeper and printing from NSDK, grant the application android.permission.MANAGE\_NEWLAND\_PAYCOMMON and NEWLAND payment common permissions to allow access to these general functions.

**"Q4: Does connecting a third-party application with PaymentLink require any special handling?"**

After importing the core AAR package of PaymentLink, the third-party application will automatically attempt to connect with the PaymentLink service upon startup. PaymentLink manages the subsequent connection process automatically. In cases of service disconnection or reinstallation, PaymentLink will automatically handle reconnecting.