Is it possible to sign up for U-mobile postpaid plan (for example P70) and then terminate after one month? Will there be any penalties or extra charges?

I have an upcoming project which requires me to be away from my home but still within Malaysia for the next 4-5 weeks. I also will be in Singapore for 5 days during this time. My current Celcom postpaid plan is great for me 90% of the time, but for this period, I need two things which the P70 is quite suitable to offer: 15GB amount of data at a relatively low cost, PLUS the Data backpack for me to use some of that data in my 5 days in Singapore. But after this period, I have no use at all for another postpaid plan.

Can I do this all for RM70, and terminate the account after one month without any penalties/hidden charges?

Wow, excellent reply. Thank you for the details. So let me just confirm: to activate international roaming, I'll have to do either one of the those 3 choices? Since I'm not porting number but getting a new line, so I'll either have to deposit RM300 or auto debit with credit card, correct?

And the total damage, including one month's charges is RM70 + RM21.58