# Can an external identifier be stored and data from another system displayed in the customer card?
# Question

Can an external identifier be stored and data from another system displayed in the customer card?

# Answer

Yes. An external identifier can be stored in a custom or technical field. Starting from version 6.0, a technical field can be made accessible only via API and hidden in the interface. Data from an external system can also be displayed through custom fields or a custom web widget.

The synchronization method and model of external entities are chosen for a specific scenario: what data the agent needs, where the source of truth is located, and who can see or modify it.

**Details:** [Custom Fields](https://support.swarmica.ru/article/ru/124-kastomnye-polya.html) · [Custom Web Widgets](https://support.swarmica.ru/article/ru/1898-sobstvennye-vidzhety-v-swarmica-veb-plaginy.html) · [Version 6.0](https://support.swarmica.ru/article/ru/1765-obnovlenie-v60x.html)