Single Entry and Incomplete Records

Single entry bookkeeping is a simple record-keeping method where a business records only one side of each transaction instead of both. For example, when Mr. Okafor's provision store receives N5,000 from a customer, he writes down only the money received, not the corresponding sale. This method is common among small Nigerian traders who cannot afford trained accountants.

The main limitation is that single entry creates incomplete records. You cannot prepare accurate financial statements because the books won't balance. There's no way to verify if records are correct or detect theft and errors easily. Additionally, calculating profit becomes difficult and unreliable. The Inland Revenue Service also dislikes these records for tax purposes since they lack proper documentation.

Most businesses eventually must reconstruct missing information to create complete accounts, making the process time-consuming and expensive.

When a business keeps poor records, accountants use the balance sheet method to find profit or loss. Think of it like this: if you start a small phone repair shop with ₦500,000 worth of tools and stock, then six months later you have ₦750,000 in assets, you've made a profit of ₦250,000 (assuming you didn't put in extra money).

The formula is straightforward: take your closing balance sheet total, subtract your opening balance sheet total, then remove any additional capital you invested or drawings you took out. What remains is your profit or loss. For example, if a Lagos trader's shop assets grew from ₦2 million to ₦2.8 million, and she withdrew ₦300,000 for personal use without adding new capital, her profit would be ₦1.1 million.

Single entry means a business only records transactions one way—usually just in a cash book or personal notebook. Converting it to double entry means we reorganize these records using the proper accounting system where every transaction has two sides: a debit and a credit.

Think of it like this: when Mama Chioma's provision store receives ₦50,000 from a customer, single entry only notes the cash received. Double entry properly records this as a debit to Cash (asset increased) and a credit to Sales (income earned). This gives a complete picture of what happened.

To convert, you start with what the business owns and owes, then reconstruct all transactions systematically. You'll calculate missing figures like profit using the accounting equation: Assets minus Liabilities equals Capital.

When a business keeps poor accounting records, accountants must prepare final accounts using the single entry system. This means working with incomplete information like bank statements, invoices, and personal notes instead of complete double-entry books.

Imagine a Lagos trader who sells textiles but only records cash received in a notebook. To find her profit, the accountant uses the statement of affairs method—listing all assets owned and liabilities owed at the beginning and end of the year. The difference shows profit earned.

Key techniques include calculating opening and closing capital, determining cost of goods sold from available data, and reconciling cash records with bank statements. You might need to work backwards from known figures to find missing information.

Mark up and margin are two different ways traders calculate profit on goods. Mark up is the amount added to the cost price to get the selling price, shown as a percentage of cost price. Margin is the profit made, shown as a percentage of selling price. They're not the same thing, and this confuses many students.

Let's use a practical example. A trader in Lagos buys rice for ₦5,000 and sells it for ₦6,000. The mark up is ₦1,000, which is 20% of the cost price (₦1,000 ÷ ₦5,000 × 100). However, the margin is also ₦1,000 but calculated as 16.67% of selling price (₦1,000 ÷ ₦6,000 × 100). Notice the margin percentage is always lower than mark up percentage for the same profit.