Is the electromagnetic door-suction card universal?

Not universal. Blank cards are universal.

For example, the access card of a community is definitely not universal. The access card of each community is different, and the information in the chip is also different. If we use the access card of our community to open the access control of other communities, it is definitely not possible. At present, in order to ensure the personal safety and property safety of owners, many communities have set up access control, and every owner has an access card. Access cards need to apply for registration at the property management office, and will only be issued after verifying the basic information. If there are no strangers, you can't enter the community without an access card. You must register with the property management office.