Credits are the currency available in Heroes and Generals for the Heroes portion of the game. You can earn credits by participating in battles and killing enemies. The credits earned from participating in battles is the salary of the soldier(s) that qualify based on their time in battle. Higher ranked soldiers earn more salary. You can see the Soldier salary by clicking on the soldiers rank in the rank progression bar.
How to earn credits
The current system added with the Xylander Build (1-9-2015) is that you get paid for playtime. Its now that 60 minutes of time ingame is X ammount of credits. If we take rank 17 as a example, it is per 60 minutes the salary is 18500. So if you play a 30 minute game, the game will calculate Hours×Soldier salary. So its 0.50h×18500 (18500=Soldier salary of rank 17). If you stay until the end of the game, you will get a 10% bonus of credits earnings. So it will become Hours×Soldier salary×110%. The amount of credits that you receive can be increased by Veteran membership. Killing tanks is the other way to earn credits with a bonus given to defense kills, capturing control points and destroying vehicles.
what are credits used for
You can spend credits on various weapons, equipment, weapon modifications, vehicles, planes and new soldiers. Each weapon and vehicle that is used will have a repair or refill cost associated with it in credits. The more advanced the weapon or vehicle, the higher the cost will be. There is an option to auto-repair items with credits, and if this option is selected then a notification will be sent following each battle giving the repair cost.