If anyone wants to do any business in Bangladesh, they must accept the electronic Business Identification Number (BIN). It is a nine-digit number that may be used to identify a taxpayer. In Bangladesh, the only authority to provide the BIN is the National Board of Revenue (NBR). The procedure to obtain BIN is as follows:
Step 1: If the limit of the annual turnover of one’s economic activities exceeds the prescribed limit; an application has to be submitted to the Commissioner in Form VAT 2.1.
Step 2: After proper scrutiny and examination, a Registration Certificate/Turnover Tax Enlistment Certificate will be issued in his/her favor in Form VAT 2.1 containing Business Identification Number (BIN) from the VAT system within 3 (three) days.
Required documents:

1. Authorized Person Details
2. All Directors’ NID/Passport
3. Business Classification Code
4. Major Area of Economic Activity
5. All Bank Statement
6. Trade Licence
7. TIN Number
8. Last e-BIN Number

Further information can be found here: National Board of Revenue (NBR)