Byproduct vs Scrap: Accounting Treatment Compared

The byproduct vs scrap accounting treatment distinction hinges on materiality and relative sales value. Both emerge as incidental output from manufacturing, but byproducts are intentional co-products with measurable sales value, while scrap is residual waste. Under accounting standards, byproducts are recognized either by offsetting their net realizable value against joint production cost or as other income, while scrap is typically treated as a gain on disposal or reduction of manufacturing cost.

Defining byproducts and scrap

In manufacturing, byproducts and scrap are both unintended or incidental outputs from the primary production process. The key difference lies in intention and value.

A byproduct is a secondary output that emerges necessarily from production of the main product—and for which management has an active sales strategy. Examples include:

• Whey from cheese production (sold for animal feed or processed into protein powder)
• Sawdust from lumber mills (sold for animal bedding or biofuel)
• Molasses from sugar refining (sold to distilleries)
• Leather trim from garment cutting (sold to leather goods makers)

A scrap is the residual waste left over after production—usually low-value material with uncertain or opportunistic market demand:

• Metal shavings and trimmings (sold to scrap dealers)
• Paper and cardboard waste (sold for recycling)
• Off-spec or damaged goods (sold at deep discount or destroyed)
• Production line rejects (melted down or composted)

The accounting distinction matters because byproducts generate predictable, material revenue streams, while scrap is often treated as a minor disposal gain or cost reduction. There is no absolute threshold, but a byproduct typically represents 5–10% or more of the main product’s revenue, while scrap is negligible by comparison.

The two byproduct recognition methods

Accounting standards (both IFRS and GAAP) permit two methods for recognizing byproduct revenue: the net realizable value (NRV) method and the other income method.

Net realizable value (offset) method

Under the NRV method, the expected sales value of the byproduct—less any separable costs of sale—is deducted from the joint production cost of the main product. This reduces the cost of goods sold (COGS) of the primary output.

Example: A cheese factory incurs $500,000 in joint production cost (milk, culture, processing). It produces 10,000 units of cheese and 2,000 gallons of whey. Whey sells for $5 per gallon; separable selling costs are $0.50 per gallon.

• Whey NRV = (2,000 gallons × $5) − (2,000 gallons × $0.50) = $9,000
• Adjusted joint cost = $500,000 − $9,000 = $491,000
• COGS per cheese unit = $491,000 ÷ 10,000 = $49.10 (vs. $50 without byproduct offset)

This method assumes the byproduct value is predictable and integral to the production process. It is the most common approach when byproduct output is reliably proportional to main product output.

Other income method

Under the other income method, byproduct revenue is recognized separately as a gain or credited to revenue (or operating income) only at the point of sale or when separable revenue is realized. No adjustment is made to joint cost allocation.

Same example:

• Cheese COGS = full $500,000 ÷ 10,000 units = $50 per unit
• Whey revenue (or other income) = $9,000, recognized at point of sale
• Net income effect is identical, but timing and statement presentation differ

This method is preferred when:

• Byproduct sales are sporadic or volumes are unpredictable
• Byproduct quality or specifications vary, affecting salability
• Management treats the byproduct as a secondary concern with no guaranteed market

Scrap accounting treatment

Scrap typically does not qualify for the byproduct methods above. Instead, accounting for scrap depends on its materiality and the point of realization:

If scrap is immaterial: It is often handled as a minor cost reduction within manufacturing overhead or absorbed into indirect cost allocation. The assumption is that scrap disposal costs roughly offset scrap sales revenue.

If scrap is material and has reliable sales value: It may be treated similarly to a byproduct under either method:

• Deducted from joint cost at a standard or budgeted value (reducing main product COGS)
• Recognized as other income only when sold

If scrap has no reliable sales value or is a loss: The cost of disposal is added to manufacturing cost or recorded as a loss.

The key distinction: scrap accounting is more often “at point of disposal” because scrap value is uncertain until the material actually sells. Byproduct accounting may be “at point of production” because the market for the byproduct is more stable and foreseeable.

Practical example: joint cost allocation with byproduct

Consider a chemical plant producing fertilizer and herbicide from the same raw materials. Joint production cost is $200,000. The plant yields:

• Fertilizer: 5,000 kilos (main product); sells for $30/kilo
• Herbicide: 1,500 kilos (byproduct); sells for $12/kilo
• Production scrap: 500 kilos (negligible value; treated as disposal cost of $2,000)

Using NRV method for byproduct:

• Herbicide NRV = 1,500 × $12 = $18,000 (assume no separable costs)
• Adjusted joint cost = $200,000 − $18,000 = $182,000
• Fertilizer cost per kilo = $182,000 ÷ 5,000 = $36.40
• Total fertilizer value at cost = $182,000
• Herbicide credited at $18,000 (reducing overall product cost)

Using other income method:

• Fertilizer COGS = full $200,000 ÷ 5,000 = $40/kilo
• Herbicide revenue = $18,000 (recognized at sale or production, depending on policy)
• Scrap disposal cost = $2,000 (added to COGS or recorded separately)

Neither method is “correct” universally; the choice depends on the nature and predictability of byproduct supply and management’s strategic focus.

When to reclassify scrap as byproduct

A material historically treated as scrap may become a byproduct if:

• Market demand grows and sales value becomes predictable (e.g., old tech waste becomes valuable as rare-earth material recovers value)
• The company invests in separable processing to increase quality (e.g., trim becomes finished leather goods)
• Volume and proportion of incidental output stabilize over time

When this occurs, accounting policy should be updated to reclassify the output as a byproduct and apply one of the two recognition methods. The notes to financial statements should disclose the change in estimate or policy.

See also