CA Intermediate · Cost and Management Accounting

Joint Products and By Products: CA Intermediate Cost and Management Accounting

Joint products come from one process, share common costs up to the split-off point, and are all major sales items. By-products are minor outputs. To solve questions, find the split-off point, apportion joint cost by the stated method (physical units, sales value or NRV), then treat by-product income as the question directs.

What this chapter covers

This chapter deals with processes that give more than one output from the same raw material and the same operations. Think of refining crude oil, milling grain or processing milk. Up to the split-off point, the cost of the process cannot be traced to any single output. It is a joint cost. After that point, each product may take its own separate cost.

The chapter has two jobs. First, you must share the joint cost among joint products, using methods such as physical units, average unit cost, sales value at split-off, sales value after further processing, and net realisable value (NRV). Second, you must deal with by-products, which are minor in value, and decide how their income or cost is shown in the accounts.

This chapter links directly to Process Costing, where abnormal loss, scrap and output of several products appear together. It also feeds into cost sheets, pricing and decision making. The further processing decision uses incremental thinking, which you will meet again in relevant costing and short-term decisions. Questions are often numerical, so MCQs test quick calculation and written answers reward a neat statement.

The chapter is compact and the logic is repetitive, so you can become fast and accurate in a short time. Questions are calculation-driven, which suits step marking in the 70-mark descriptive part and suits quick MCQs in the 30-mark part, where there is no negative marking. A clear apportionment table, correct NRV working and a stated decision earn marks even if one number slips. The same ideas also support Process Costing and decision-making questions elsewhere in the paper, so your effort here pays back more than once.

Joint Products and By Products: topics in the order to study them

1Joint Products and By-Products: Meaning and DifferencesYou need the definitions, the split-off point and the test of 'major versus minor' before any calculation makes sense.
2Apportionment of Joint Costs to Joint ProductsThis is the core numerical skill, and every later topic builds on a correct allocation of joint cost.
3Net Realisable Value and Further Processing DecisionsNRV is an apportionment method and also the base for deciding whether to process further, so it follows the basic methods.
4Accounting Treatment of By-ProductsStudy it last, because it modifies the joint cost to be apportioned. Where by-product value is deducted, the net joint cost after the by-product credit is what you share among the joint products, so this topic builds on the apportionment methods you have already learned.

How to prepare Joint Products and By Products

Treat the chapter as one repeatable routine: identify outputs, find the split-off point, choose the method the question states, and finish with a clear conclusion. Practise each step until it is automatic.

Write down the definitions of joint product, by-product, joint cost and split-off point in your own words, with one real example of each.
Learn each apportionment method as a short recipe: the base used, the ratio formed, and the cost share per product. Practise a small question on each method.
Always build a table with products in columns and rows for base, ratio, joint cost share, separate cost and total cost. Use it every time.
For NRV, compute final sales value less further processing cost and less selling or distribution cost. Then apportion joint cost on this NRV, if the question says so.
For further processing decisions, ignore the joint cost, since it is the same either way. Compare incremental revenue with incremental cost for each product separately.
Practise the by-product treatments precisely, and follow the wording of the question: (i) credit the total sales income of the by-product to the profit and loss account; (ii) deduct the net realisable value of the by-product (sales less its separate processing and selling costs) from the joint cost of the main products; (iii) the reverse cost method, where the by-product's NRV, less its own costs after split-off and a normal profit margin, is credited to the joint process.
Finish with mixed questions under time limits, and check each answer by confirming that the shares add back to the total joint cost.

Common mistakes in Joint Products and By Products

Including joint cost in the further processing decision
Fix: Treat joint cost as sunk because it does not change with the decision. Compare only extra revenue and extra cost after split-off.
Using the wrong base for apportionment
Fix: Underline the method named in the question. If none is named, state your choice and give the reason in one line.
Forgetting to deduct selling and further processing costs in NRV
Fix: Write NRV as final sales value less further processing cost less selling cost, as a labelled row in your table.
Treating a by-product like a joint product
Fix: Check the question wording for 'by-product'. Then follow the stated treatment and do not apportion joint cost to it unless asked.
Mixing up input units and output units
Fix: Write a quick quantity reconciliation first. Use good output units for physical-unit apportionment and for per-unit cost.
Not stating a conclusion
Fix: End with one sentence, such as 'Product X should be processed further because incremental profit is ₹__', and label totals and per-unit costs clearly.

Last-day revision: Joint Products and By Products

Joint cost is the cost of a common process up to the split-off point.
Joint products are all major products of value; by-products are minor outputs of low value.
Costs after split-off are separable costs and are charged directly to the product.
Physical unit method shares joint cost in the ratio of quantities produced.
Sales value at split-off method shares joint cost in the ratio of sales value at that point.
NRV method uses final sales value less further processing and selling costs.
Joint cost already incurred is sunk, so ignore it in further processing decisions.
Process further only if incremental revenue is more than incremental cost.
Check that apportioned shares add up to the total joint cost.
By-product income may be credited to profit and loss or deducted from joint cost, as stated.
Read units carefully: use output units, and watch for losses and opening or closing stock.

Joint Products and By Products practice questions

Joint Products and By Products in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Joint Products and By Products: frequently asked questions

What is the difference between joint products and by-products?

Joint products are the main outputs of a common process and each has significant sales value. By-products are secondary outputs of relatively small value. The difference is judged by relative importance, not by the process itself.

Which apportionment method should I use if the question does not name one?

Choose the method that fits the data given. Sales value or NRV is usually more suitable when selling prices are provided, as it links cost to ability to bear it. State your choice in one line so the examiner can follow your logic.

Why is joint cost ignored in a further processing decision?

Joint cost is incurred before the split-off point and is the same whether you sell at split-off or process further. It is therefore not relevant. Only the extra revenue and extra cost after split-off matter.

How should I prepare this chapter for the MCQs?

Practise short calculations on each method until you can do them quickly. Learn the definitions and the logic of sunk joint cost. There is no negative marking, so always attempt every MCQ.