customer copy
Polite term used in business settings for the copy of a receipt, contract, or form given to the customer.
Here is your customer copy of the receipt.
Please keep the customer copy of the contract in a safe place.
領収書 is a formal receipt; お客様控え can be the customer's copy of a receipt or other document.
Standard polite spelling used in business contexts.
Abbreviated spelling sometimes seen on receipts or forms.
Compound of お客様 (customer, polite) + 控え (copy, duplicate).