Assurance and Financial Statement Auditing The attesting adds another layer of quality assurance with regard to the auditing of the financial reports...

Assurance and Financial Statement Auditing

The attesting adds another layer of quality assurance with regard to the auditing of the financial reports and it is an important service used by many large corporations. 

For example, would be able to identify if Costco uses attesting services for its financial statement reporting? If yes, please specify which entity attests Costco's financial reports.