Arthur agreed to complete the annual tax return for Patrick in July and received all of the necessary information from Patrick then. Arthur unfortunately forgot to do the work for 6 months, and upon realising, quickly completed the returns and sent them to Patrick for signing with an invoice of $200. Patrick does not want to pay the $200 as he had the annual tax return completed by another Tax Agent after not hearing from Arthur for 2 months. Patrick is seeking your advice as to whether he needs to pay the $200 invoice.