Test ID-card can only be used in test environment. Test ID-card certificates cannot be renewed.
Additional info about different ID-card generations is available at id.ee.
How does the test card work?
The issued test cards have test certificates that are similar to real card certificates, but they cannot be used for giving digital signatures with legal force, because the cardholder does not exist in reality. Test cards can be used against SK's test services. Additional information about testing can be found here.
SK issues test cards whose fictitious cardholder name contains the letters Ä or Ž in the UTF-8 coding. This way you can test the character support in your applications. You can access the user manual of the test card here:
SK test certification hierarchy is described here.
Corporate test certificate on a crypto stick is free, but you have to pay for the crypto stick. The crypto stick can later be used with the certificate from production CA as well. See the price list here.
Using a test card in SK's test services is free of charge.