Journal Entry Fundamentals: Master Debit & Credit with 15 Real-World Scenarios

What Is a Journal Entry?

A journal entry is the foundational recording method in double-entry bookkeeping. Every financial transaction is recorded simultaneously on two sides: Debit (Dr) and Credit (Cr).

The Basic Debit/Credit Rules

What Goes on the Debit Side (Dr)

Account Type	Increase	Decrease
Assets	Debit	Credit
Expenses	Debit	Credit

What Goes on the Credit Side (Cr)

Account Type	Increase	Decrease
Liabilities	Debit	Credit
Equity	Debit	Credit
Revenue	Debit	Credit

Memorize the increase/decrease direction for these 5 account types (assets, liabilities, equity, revenue, expenses) and you can logically work out any journal entry.

The Accounting Equation

Every journal entry must maintain this equation:

Assets = Liabilities + Equity

This is why debits must always equal credits — both sides of the equation must stay balanced.

Practice: Journal Entry Trainer

Work through 15 real-world scenarios below. Each answer reveals a T-account visualization.

회계 분개 연습기

점수: 0/15(1/15)

문제 1

현금으로 매출 100만원 발생

Cash sales of 1,000,000 won

금액: 1,000,000원

차변 계정 (Dr)-- 계정 선택 --현금매출채권재고자산유형자산감가상각누계액선급비용미수수익매입채무선수금차입금사채자본금이익잉여금매출매출원가급여감가상각비이자비용법인세비용배당금

대변 계정 (Cr)-- 계정 선택 --현금매출채권재고자산유형자산감가상각누계액선급비용미수수익매입채무선수금차입금사채자본금이익잉여금매출매출원가급여감가상각비이자비용법인세비용배당금

정답 확인

분개 원칙: 차변 = 자산 증가 · 비용 발생 | 대변 = 부채·자본 증가 · 수익 발생

Common Mistakes to Avoid

1. Prepaid Expense vs. Unearned Revenue

Prepaid Expense: Future benefit paid upfront → Asset (Debit)

• Example: Prepaid rent → Prepaid Expense / Cash

Unearned Revenue (Advance): Cash received before delivery → Liability (Credit)

• Example: Deposit received → Cash / Advances Received

2. Depreciation

Depreciation expense (Debit) is offset by Accumulated Depreciation — a contra-asset account (Credit), not a direct reduction of the asset.

Depreciation Expense    ×××
  Accumulated Depreciation  ×××

3. Collecting Accounts Receivable

Collecting on a credit sale is not new revenue. The revenue was already recorded. This is simply an asset swap: A/R converts to Cash.

Cash               ×××
  Accounts Receivable  ×××

4. Accrued Interest Expense

Under accrual accounting, interest owed but not yet paid is still an expense for the current period.

Interest Expense   ×××
  Accrued Liabilities  ×××