1You have been assigned to perform tests of controls on the sales system at Shop 'n Ship Ltd. as part of the December 31, 2020, audit. Shop 'n Ship is a wholesaler of bathroom supplies such as vanity units, toilets, taps, and sinks. During testing, you noted the following errors:

1.Invoice no. 54922 issued on January 12, 2020, was entered twice. The error was discovered whenthe customer phoned to complain about being charged double the agreed amount.

2.Invoice no. 62875 issued on November 29, 2020, was not processed through the usual channels. Thedetails were correct but certain procedures, such as a formal credit check, were not documented. The invoice was a special order for a large building project and amounted to around 10 times thevalue of Shop 'n Ship's average invoices. The sale was personally handled by one of the directors and the invoice was prepared by his assistant.

3.No prices were entered on invoice no. 56329 issued on April 24, 2020, resulting in a zero dollarinvoice being issued. The error was discovered when accounts receivable staff noticed the zeroamount appearing on the accounts receivable ledger.

4.Invoice no. 59328 issued on July 18, 2020, matched the customer's order. However, the order wasonly partially filled because of a lack of inventory in the warehouse, meaning items that were neverdelivered were included in the invoice. The error was discovered when the customer phoned tocomplain about being overcharged.

Required

Treating each of the listed errors independently:

a.Recommend an application controlthat would have prevented or detected the error.

b.What account(s) are affected?What assertion(s) are at risk?

c.Document a substantive testof accounts receivable to address the at risk assertion(s).

Item a) Application b) Account + c) Substantive control assertion at risk audit procedure recommendation 2 3 4