Bangladesh SIM USSD code, keep saving. Maybe you will not receive urgent needs:

বাংলাদেশের সকল সিমের ইউএসএসডি কোড, সংরক্ষণে রাখুন ॥ জরুরী প্রয়োজনের হয়তো পাবেন না :

Grameen Phone
Balance Check : *566#
Show SIM Number : *2#
Package Check : *111*7*2#
Minute Check : *566*24# , *566*20#
SMS Check : *566*2#
MMS Check : *566*14#
Data (MB) Check : *566*10# , *567#
Call Me Back : *123*Number#
Net Setting Request : *111*6*2#
Miss Call Alert (On) : type START MCA & Send to 6222
Miss Call Alert (Off) : Type STOP MCA & Send to 6222

Banglalink
Balance Check : *124#
Show SIM Number : *511#
Package Check : *125#
Minute Check : *124*2#
SMS Check : *124*3#
MMS Check : *124*2#
Data (MB) Check : *124*5# , *222*3#
Call Me Back : *126*Number#
Net Setting Request : Type ALL & Sent to 3343
Miss Call Alert (On) : Type START & Send to 622
Miss Call Alert (Off) : Type STOP & Send to 622

Robi
Balance Check : *222#
Show SIM Number : *140*2*4#
Package Check : *140*14#
Minute Check : *222*3#
SMS Check : *222*11#
MMS Check : *222*13#
Data (MB) Check : *222*81# , 8444*88#
Net Setting Request : *140*7#
Miss Call Alert (On) : Type ON & Send to 8272
Miss Call Alert (Off) : Type OFF & Send to 8272

Airtel
Balance Check : *778#
Show SIM Number : *121*6*3#
Package Check : *121*8#
Minute Check : *778*5# or *778*8#
SMS Check : *778*2#
MMS Check : *222*13#
Data (MB) Check : *778*39# or *778*4#
Call Me Back : *121*5#
Net Setting Request : *140*7#
Miss Call Alert (On) : *121*3*4#

Teletalk
Balance Check : *152#
Show SIM Number : Type “Tar” & send to 222
Package Check : unknown
Minute Check : *152#
SMS Check : *152#
MMS Check : *152#
Data (MB) Check : *152#
Net Setting Request : Type SET & Send to 738
Miss Call Alert (On) : Type REG & Send to 2455
Miss Call Alert (Off) : Type CAN & Send to 245