There are two major ways you can lose credits on A3.
Firstly, if you are alive and happen to have credits in your hand (rather than in the bank), other aliens are able to kill you and take what you are carrying. The only way to avoid this is to register for merchant status, or to quickly deposit any money you receive in the bank.
If credits are disappearing from your bank account, the reason is that you have a bank loan. After a certain period of time (if you have not paid back the loan), the bank will begin deducting a % of credits from your bank account everytime you use your B.O.W. card.



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