Cost accounting is no longer simply a matter of record-keeping; it has become the "heart" of a business's strategic management system. Accurately determining the cost of producing a product helps businesses optimize profits, enhance competitiveness, and ensure transparency with tax authorities. This article will provide a comprehensive and up-to-date overview of the processes, methods, and technological trends in cost accounting.
What is cost accounting?
Cost accounting is a crucial subsystem of management accounting and financial accounting, focusing on the collection, analysis, and allocation of costs incurred in the production and business process to determine the actual value of a unit of product or service.
By 2026, this concept will be expanded to integrated cost management. It will not only encompass tangible costs but also carbon costs (ESG), digital licensing costs, and smart operating costs. A skilled cost accountant needs not only to know how to add and subtract numbers but also to have a deep understanding of technical standards and factory operating procedures.
Distinguishing between cost accounting and expense accounting.
Many people often confuse these two concepts. However, technically, there are clear distinctions between them to avoid confusion during accounting:
- Cost accounting: Focuses on aggregating all incurred costs (inputs) according to each cost element such as materials, wages, and outsourced services.
- Cost accounting: This is the final result of the cost accumulation process, linked to a specific product (output). If cost accounting answers the question "How much money have we spent?", then cost accounting answers the question "How much does it cost to produce one product?".
The strategic role of cost accounting
In the context of volatile inflation and globalized supply chains today, cost accounting plays an extremely important role for businesses:
- Strategic pricing basis: Helps the sales department determine floor and ceiling prices to ensure target profit margins. If cost accounting data is inaccurate, the business may unknowingly sell below cost.
- Optimizing production resources: Identifying cost bottlenecks to reduce waste in the production line.
- Legal compliance and tax optimization: Ensuring that the figures on financial statements accurately reflect actual production. To ensure high professionalism and minimize the risk of errors, many businesses now prioritize choosing specialized service providers. full accounting service It is important to have a good reputation for handling cost issues systematically from the outset.
Detailed cost accounting process
To perform cost accounting scientifically, accountants need to adhere to a strict four-step process, combined with the support of ERP software systems and modern AI algorithms.
Step 1: Gather production costs incurred during the period.
This stage involves collecting all original documents related to the production process. According to the current accounting regulations (Circular 200), cost accounting expenses are grouped into three main categories:
- Direct material costs (Account 621): Includes the value of raw materials, main materials, and auxiliary materials that are directly used. For example, in garment manufacturing, cost accounting will accumulate the costs of fabric, thread, and buttons into this account based on production warehouse withdrawal slips.
- Direct labor costs (Account 622): Includes salaries, wages, and deductions from salaries (social insurance, health insurance, union fees) of direct production workers. Cost accountants need to compare time sheets with payroll records to ensure accuracy.
- General production costs (Account 627): Indirect costs in the workshop such as machinery depreciation, electricity and water costs, and salaries of workshop management staff. This is the most difficult part to allocate in cost accounting. Therefore, businesses can refer to the following: outsourced accounting services Seek support from a reputable and experienced provider like MAN – Master Accountant Network.
Step 2: Classify and allocate costs
For costs that cannot be directly separated for each product, cost accounting needs to choose an appropriate allocation method:
- Allocation based on the proportion of main raw material costs: Applicable when the product consumes a large amount of raw materials.
- Allocation based on actual working hours: Applicable to labor-intensive industries.
- Allocation based on machine hours: Particularly common in automated factories.
Step 3: Inventory and valuation of work-in-progress at the end of the period.
Evaluating work-in-progress is a crucial step in determining the accuracy of cost accounting. There are three most common methods:
- Valuation based on the cost of primary materials: This method is simple, only calculating the value of materials included in the work-in-progress.
- Valuation based on equivalent completed output: Cost accounting converts work-in-progress into completed products based on the degree of completion (Example: 200 work-in-progress items = 100 completed items).
- Cost-based evaluation: Applicable when the business has an accurate cost standardization system.
Step 4: Calculate the total cost and unit cost.
Once all the data is available, the cost accountant applies the following formula:
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Total cost = Beginning work-in-process costs + Costs incurred during the period – Ending work-in-process costs |
In there:
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Unit cost = Total cost / Number of finished products |
Common cost calculation methods
The choice of cost accounting method depends on the technological characteristics and production processes of each enterprise.
Direct method
This is the most basic method in cost accounting.
- Target audience: Businesses that produce a small number of product lines and have simple processes (e.g., mineral extraction).
- Practical example: A quarry calculates all expenses incurred during the month and divides them by the number of cubic meters of stone extracted.
Coefficient Method
The challenge for cost accounting using this method is determining the correct conversion factor.
- Target audience: Manufacturing that produces multiple products from the same process (e.g., clothing in various sizes).
- Calculation method: Convert all products to standard sizes using a coefficient (size M = 1, size L = 1.2, size XL = 1.5).
Ratio Method
Cost accounting often applies this method in industries such as confectionery and cosmetics.
- Characteristics: Costs are aggregated for each product group, then proportionally divided based on the standard cost or selling price.
Byproduct Elimination Method
In the agricultural or chemical industries, determining the value of by-products is a crucial task of cost accounting.
The cost calculation formula is determined as follows:
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Cost of the main product = Total costs – Value of recovered by-products |
Step-by-Step Method
This applies to production lines with multiple consecutive stages. Cost accounting must calculate the cost for each semi-finished product at each step before adding them up.
Order Method
Commonly seen in the construction or shipbuilding industries, cost accountants will open a detailed ledger for each order, and the costs are "held" in account 154 until the order is delivered.
Guidelines for cost accounting according to Circular 200 and Circular 133
The differences in the accounting system between these two circulars require cost accounting staff to pay close attention:
According to Circular 200/2014/TT-BTC
Cost accounting according to Circular 200/2014/TT-BTC:
- Cost aggregation: Debit 621, 622, 627 / Credit 152, 334, 214…
- Closing entries at the end of the period: Debit 154 / Credit 621, 622, 627.
- Finished goods inventory entry: Debit 155 / Credit 154.
According to Circular 133/2016/TT-BTC
For SMEs, the work of a cost accountant is simplified:
- Cost aggregation: Debit 154 (Details for each element) / Credit 152, 334, 214…
- Finished goods inventory entry: Debit 155 / Credit 154.
Common errors and how to handle them in cost accounting.
Below are tips from MAN – Master Accountant Network for cost accountants to avoid expense disallowances during tax settlement:
- Material waste exceeding the standard: If the cost in account 621 is unusually high compared to the technical standard without a reasonable explanation, the tax authorities have the right to disallow this excess cost. The cost accountant needs to prepare a report confirming the cause (due to poor quality materials, machinery malfunction).
- Incorrect allocation of overhead costs: Inconsistent selection of allocation methods across years can lead to artificial fluctuations in cost of goods sold. Cost accounting needs to maintain a consistent method for at least one accounting period.
- Misinterpreting selling expenses and administrative expenses: Many businesses include office expenses in account 627 to increase the cost of goods sold. This is a serious mistake that cost accountants need to avoid.
Checklist of 10 steps for professional cost accounting.
To ensure a perfect cost accounting record, follow this checklist:
- Have you updated your Bill of Materials (BOM) to the latest version?
- Do the delivery notes clearly specify the cost aggregation object?
- Does the time sheet clearly separate direct workers from management staff?
- Do the electricity, water, and factory rent bills include the company's full name and tax identification number?
- Is the method for evaluating work-in-progress consistent with last year?
- Has a physical inventory count been conducted at the end of the period?
- Has the value of recovered scrap (if any) been deducted from the cost?
- Is the allocation of overhead costs changing unusually?
- Have all the balances of accounts 621, 622, and 627 been transferred to account 154 yet?
- Do the data in the accounting software match the Excel costing spreadsheet (if used)?
Conclude
Cost accounting has never been an easy job, but it is the true measure of a professional finance practitioner's value. In the context of 2026 technology, the line between a purely record-keeping accountant and a strategic cost management expert lies in the ability to master numbers and apply technology to optimize cash flow for the business.
If your business is struggling to establish a costing system, choose the optimal allocation method, or wants to apply AI tools to its operational processes, don't hesitate to contact MAN – Master Accountant Network for detailed support and advice.
Source:
Contact information MAN – Master Accountant Network
- Address: No. 19A, Street 43, Tan Thuan Ward, Ho Chi Minh City
- Mobile/Zalo: 0903 963 163 – 0903 428 622
- Email: man@man.net.vn
Content production by: Mr. Le Hoang Tuyen – Founder & CEO MAN – Master Accountant Network, Vietnamese CPA Auditor with over 30 years of experience in Accounting, Auditing and Financial Consulting.
