As a basic principle , ACME AG receives invoices on paper or fax . These are received by the Secretariat in the central inbox and forwarded after a short visual inspection to an accounting employee . In `` ACME Financial Accounting `` , a software specially developed for the ACME AG , she identifies the charging suppliers and creates a new instance ( invoice ) . She then checks the invoice items and notes the corresponding cost center at the ACME AG and the related cost center managers for each position on a separate form ( `` docket `` ) . The docket and the copy of the invoice go to the internal mail together and are sent to the first cost center manager to the list . He reviews the content for accuracy after receiving the copy of the invoice . Should everything be in order , he notes his code one on the docket ( `` accurate position - AP `` ) and returns the copy of the invoice to the internal mail . From it , the copy of the invoice is passed on to the next cost center manager , based on the docket , or if all items are marked correct , sent back to accounting . Therefore , the copy of invoice and the docket gradually move through the hands of all cost center managers until all positions are marked as completely accurate . However , if inconsistencies exist , e.g . because the ordered product is not of the expected quantity or quality , the cost center manager rejects the AP with a note and explanatory statement on the docket , and the copy of the invoice is sent back to accounting directly . Based on the statements of the cost center managers , she will proceede with the clarification with the vendor , but , if necessary , she consults the cost center managers by telephone or e-mail again . When all inconsistencies are resolved , the copy of the invoice is sent to the cost center managers again , and the process continues . After all invoice items are AP , the accounting employee forwards the copy of the invoice to the commercial manager . He makes the commercial audit and issues the approval for payment . If the bill amount exceeds EUR 20 , the Board wants to check it again ( 4 - eyes-principle ) . The copy of the invoice including the docket moves back to the accounting employee in the appropriate signature file . Should there be a complaint during the commercial audit , it will be resolved by the accounting employee with the supplier . After the commercial audit is successfully completed , the accounting employee gives payment instructions and closes the instance in `` ACME financial accounting `` .