The first time you are paying with the invoice option, a credit check will take place. According to Swedish law, information regarding the check will be sent to you in the mail. 

Together with the credit check and other information an overall assessment is made of your financial wellbeing and a credit limit is set. The credit limit can not be changed manually but will be changing overtime. For ex. if you pay your invoices in time, your credit limit will be raised gradually. However, if you are late with your payments, your credit limit will be reduced. 

Good to know since we are present on gambling sistes we are quite conservative in your evaluation.