Does Credit Limit will only take care site level but not account level when set both level?

Dear guru,

I met one issue as below.

If we set credit limit at customer account and account site level, for example, credit limit 20k at cutsomer account level, and there are two sites, each site set credit limit at 15k. When I create two sales order for each site, each order amount is 15k, and both sales order does not hold. So does that mean if customer site credit limit check passed, it will not check customer account level credit limit?

Thank you

Charley