There are two types of transfer online: type 1. bank-to-bank transfers between your own accounts. You can do a deposit or a debit.
Type 2. transfer money to someone else’s bank account. You can only do a deposit!
The critical security for first type transfer is that, you’ll have to prove that the other account is yours, usually by providing two small amounts of transferred money between the two banks. The second type will never need it!
If someone asks you to provide two small amounts of money of transfer then you must be alerted! You should never give these two small amounts of money to anyone because this verification process is specific for your own account transfer ONLY!
If you give these two amounts of transfer to someone else then you may lose your money because your account is linking to the account of scammers. They can transfer your money from your bank to their banks!
For instance, you tenant may ask you for your bank account number for rent deposit but they should never ask you to provide two amounts of money transfer!