Principles of Financial Accounting: The Accounting Equation and Double Entry - DoubleEntry System, Debits and Credits TAccounts

What It Is

The Double-Entry System is a fundamental concept in financial accounting that records business transactions by debiting and crediting accounts simultaneously. This system ensures that every transaction affects at least two accounts, maintaining the accounting equation: Assets = Liabilities + Equity. If a company buys $10,000 of inventory, the transaction would be recorded by debiting Inventory ($10,000) and crediting Cash ($10,000).

Key Concepts & Formulas

• Debit: A left-side entry in a T-account, increasing asset or expense accounts, or decreasing liability or equity accounts. Example: Debit Cash ($1,000) to record a cash receipt.
• Credit: A right-side entry in a T-account, increasing liability or equity accounts, or decreasing asset or expense accounts. Example: Credit Accounts Payable ($1,000) to record a purchase on credit.
• Assets: Resources owned or controlled by a business, increasing with debits and decreasing with credits. Example: Debit Cash ($5,000) to record a cash deposit.
• Liabilities: Debts or obligations owed by a business, increasing with credits and decreasing with debits. Example: Credit Accounts Payable ($5,000) to record a purchase on credit.
• Equity: Ownership interest in a business, increasing with credits and decreasing with debits. Example: Credit Retained Earnings ($5,000) to record a dividend distribution.
• Gross Profit: Sales revenue minus Cost of Goods Sold (COGS). Example: Gross Profit = $100,000 (Sales) - $60,000 (COGS) = $40,000.
• Net Income: Gross Profit minus Operating Expenses. Example: Net Income = $40,000 (Gross Profit) - $20,000 (Operating Expenses) = $20,000.
• Debit/Credit Rules: Debit what increases, credit what decreases (Assets, Expenses, Dividends) or debit what decreases, credit what increases (Liabilities, Equity, Revenue).

Journal Entry Examples

Example 1: Purchase of Inventory on Credit

Dr. Inventory $10,000 Cr. Accounts Payable $10,000

Explanation: Debit Inventory to record the increase in assets, and credit Accounts Payable to record the increase in liabilities.

Example 2: Sale of Inventory on Cash

Dr. Cash $5,000 Cr. Sales Revenue $5,000

Explanation: Debit Cash to record the increase in assets, and credit Sales Revenue to record the increase in revenue.

Example 3: Payment of Accounts Payable

Dr. Cash $5,000 Cr. Accounts Payable $5,000

Explanation: Debit Cash to record the decrease in assets, and credit Accounts Payable to record the decrease in liabilities.

Common Mistakes

Mistake 1: Confusing Debits and Credits for Expense Accounts

• Correction: Debit what increases, credit what decreases (Assets, Expenses, Dividends) or debit what decreases, credit what increases (Liabilities, Equity, Revenue).
• Mnemonic: "ADE" (Assets, Drawings, Expenses) for debits, and "LED" (Liabilities, Equity, Dividends) for credits.

Mistake 2: Ignoring Normal Balances

• Correction: Assets and Expenses have normal debit balances, while Liabilities, Equity, and Revenue have normal credit balances.
• Mnemonic: "ADE" (Assets, Drawings, Expenses) for debits, and "LED" (Liabilities, Equity, Dividends) for credits.

Mistake 3: Reversing Normal Balances

• Correction: Assets and Expenses have normal debit balances, while Liabilities, Equity, and Revenue have normal credit balances.
• Mnemonic: "ADE" (Assets, Drawings, Expenses) for debits, and "LED" (Liabilities, Equity, Dividends) for credits.

Exam Tips

• Tip 1: A debit increases assets AND expenses – remember "ADE" (Assets, Drawings, Expenses).
• Tip 2: A credit increases liabilities AND equity – remember "LED" (Liabilities, Equity, Dividends).
• Tip 3: Be careful with reversing normal balances – it's a common trap.

Quick Practice

Problem 1: Purchase of Inventory on Credit

A company purchases $10,000 of inventory on credit. What is the journal entry?

Answer: Dr. Inventory $10,000, Cr. Accounts Payable $10,000

Explanation: Debit Inventory to record the increase in assets, and credit Accounts Payable to record the increase in liabilities.

Problem 2: Sale of Inventory on Cash

A company sells $5,000 of inventory on cash. What is the journal entry?

Answer: Dr. Cash $5,000, Cr. Sales Revenue $5,000

Explanation: Debit Cash to record the increase in assets, and credit Sales Revenue to record the increase in revenue.

Problem 3: Payment of Accounts Payable

A company pays $5,000 of Accounts Payable. What is the journal entry?

Answer: Dr. Cash $5,000, Cr. Accounts Payable $5,000

Explanation: Debit Cash to record the decrease in assets, and credit Accounts Payable to record the decrease in liabilities.

Last-Minute Cram Sheet

• Assets have normal debit balances.
• Liabilities, Equity, and Revenue have normal credit balances.
• Debit what increases, credit what decreases (Assets, Expenses, Dividends) or debit what decreases, credit what increases (Liabilities, Equity, Revenue).
• Gross Profit = Sales - COGS.
• Net Income = Gross Profit - Operating Expenses.
• Dividends are NOT an expense – they go directly to retained earnings.
• Reversing normal balances is a common trap.
• Debit what increases, credit what decreases (Assets, Expenses, Dividends) or debit what decreases, credit what increases (Liabilities, Equity, Revenue).
• Assets and Expenses have normal debit balances, while Liabilities, Equity, and Revenue have normal credit balances.