You said level 5 test center upstairs, right? Band 4 can be taken at the local level. However, you can't take PETS4 on March 20 10. PETS4 is only taken once a year, that is, in September every year, and the registration time is at the end of May and the beginning of June. The specific registration time varies from place to place. This can only be asked in the local study room.

You can go to the website of the self-study office to see if there are any registration points nearby, but the self-study office can definitely register.

The process is very simple, as long as you bring your ID card (with photos in some places) to the registration point during the registration time.

You can call the self-study exam office to ask about the above. Good luck!