If you had forgotten your EPF@KWSP number and you need it urgently, you just need to make a phone call to EPF Call Management Centre (CMC) or Pusat Panggilan KWSP at 03-89226000 (operation hour: Monday-Friday, 8am-6pm). I had done this before. The CMC staff is very helpful, friendly and most importantly efficient and provide me with accurate information. When I called them to inquire my EPF number, the call was picked up in a few seconds. When I told them I need to check my EPF number, the staff asked for my IC number and my name for verification. Once verified, he gave me my EPF number accordingly. All this just take less than 2 mins.
Of course, other than calling the EPF CMC, there are other ways to get your EPF@KWSP numbers:
1) If you had i-Akaun, just log in to your i-Akaun and from there you'll get your EPF number;
2) Ask for your EPF number from your existing employer Human Resource Department;
3) If you had keep a proper filing for the yearly EPF statement, you can get the EPF number on the EPF yearly statement too;
4) Go to the KWSP offices nationwide to ask for your EPF number;
5) Go to your nearest KWSP Kiosk
But, I find the easiest and fastest way is by calling EPF CMC number at 03-89226000. EPF CMS also provide multiple services to all EPF contributors in Malaysia. For other services provided by EPF CMC, feel free to visit EPF CMC page.
For the details location of EPF branches and EPF Kiosk throughout Malaysia, feel free to visit KWSP website.
Hope the above helps :)