Costing does differ from job costing in respect of the following:
(i) A number of jobs in hand may be large while number of contracts that may be undertaken at a time may be few.
(ii) Most of the expenses are directly charged to contract account but direct allocation of expenses to such extent is not possible in job costing.
(iii) Since a contract may run for a longer period, the question of assessment of profit on incomplete contract at the end of the accounting period naturally arises while such a question does not arise in case of job costing.
(iv) The analysis, apportionment, allocation and control of cost is simple in contract costing.