The Electronic Exchange of Social Security Information system (EESSI) electronically connects social security institutions from the 27 EU Member States, Iceland, Liechtenstein, Norway, Switzerland, and the United Kingdom.
It replaces the paper-based communication between those institutions, and allows for faster, easier, and more secure exchanges of information about social benefits of people moving between those states. It was first launched in 2017 by the European Commission, and now all 32 countries mentioned above have full access to it.
These changes cover various social benefits, but let's explain the most frequent example:
When applying for public health insurance as a voluntary member in Germany, you will need to prove your EU/EEA/United Kingdom state insurance coverage.
Previously, you would have to request a paper document called E 104 from your insurance provider in your home country, wait for the issuance, and submit it to your chosen German provider.
Nowadays, you simply have to provide your insurance number from your provider in your home country. By using EESSI, the German provider can simply check your insurance history, to confirm your policy.
For more information, please visit the European Commission website.