What Is Single-Entry Bookkeeping?

Single-entry bookkeeping, also called single entry accounting, is the simplest way to keep business records: each transaction is written down once, as money in or money out, in a cash book with a running balance. There is no matching second entry and no ledger of assets or debts. It suits freelancers, sole proprietors and very small businesses that are paid in cash and hold no stock, and it stops working once a business buys on credit or carries inventory.

This guide explains how a single-entry cash book works, how to set one up, what a month of records looks like, and the signs that you have outgrown it. If you want to see single entry and double entry compared on the same transactions, read our guide to single-entry vs double-entry accounting.

What is single entry bookkeeping?

Single entry bookkeeping is a method of recording financial transactions where each transaction is entered once, as either income or an expense. There is no corresponding entry in another account. The result is a simple cash book that tracks the flow of money in and out of a business over time.

The IRS describes it in Publication 583 as a system “based on the income statement (profit or loss statement)”, and says it can be a simple and practical system if you are starting a small business. According to the IRS, a single-entry system records income and expenses through a daily summary of cash receipts and monthly summaries of cash receipts and disbursements.

Think of it like a personal bank statement. Money comes in, money goes out, and you can see the running balance. What you cannot see is what the business owns, what it owes, or what the income was for beyond a one-line description.

That is the trade-off at the heart of single-entry bookkeeping: simplicity in exchange for depth. For a business with a few dozen cash transactions a month, it is the right trade. For a business with inventory, suppliers on terms or customers who pay later, it hides the numbers that matter.

How single-entry bookkeeping works

A single-entry cash book is usually a spreadsheet. Each row is one transaction, with columns for the date, a description, a category, and the amount in or out. The running balance should match the bank balance once everything has cleared.

A month in a single-entry cash book

Here is September 2026 for a freelance designer who invoices clients and pays a few business costs.

The monthly summary

At month end, you total each column and each category. This is the monthly summary of receipts and disbursements the IRS refers to.

The closing balance should equal the bank statement balance, after allowing for any checks or deposits that have not yet cleared. That comparison is the only real check a single-entry system has, so it is worth doing every month.

Totals by category (fees, supplies, software, contract labor, bank charges) are what feed a Schedule C or a simple profit and loss summary at year end.

What the cash book does not capture

• An invoice the designer sent on September 28 that the client has not paid yet.
• A software renewal billed on a credit card that will be paid next month.
• The laptop bought last year, and how much of its value has been used up.
• Any loan balance, sales tax collected, or tax owed.

None of these are cash movements this month, so none appear. In a small service business that may not matter much. In a product business it matters a great deal.

How to set up a single-entry bookkeeping system

1. Open a separate business bank account. Keeping business and personal money apart is the single biggest help to clean records.
2. Create the cash book. A spreadsheet with columns for date, description, category, income, expense and balance is enough.
3. Choose a short list of categories that match the lines on your tax return, such as fees or sales, supplies, software, contract labor, rent, travel and bank charges.
4. Enter the opening balance from your bank statement on day one.
5. Record every transaction as it happens, or at least weekly, with a description clear enough to understand a year later.
6. Keep the evidence. Save receipts, invoices and bank statements for each entry. Publication 583 explains that records should be kept as long as they may be needed for tax purposes, generally until the period of limitations for that return runs out, which is usually three years and longer in some cases. Employment tax records must be kept for at least four years.
7. Close each month. Total receipts and disbursements, total each category, and compare the closing balance with the bank statement.

Who uses single-entry bookkeeping?

Single-entry bookkeeping is most appropriate for:

• Freelancers and sole proprietors with a few income streams and no fixed assets to speak of
• Very small service businesses where the owner handles all the money and most payments are immediate
• Side businesses and new ventures in their first months, where the priority is getting everything recorded at all
• Small clubs and community groups with simple finances and limited reporting obligations

It is generally not appropriate for businesses with inventory, employees, credit sales, loans, or anyone outside the business who expects GAAP financial statements, such as investors, lenders or a board.

Advantages of single-entry bookkeeping

• Simple to set up. No accounting software is required. A spreadsheet is enough to get started.
• Low cost. The method needs no specialist knowledge and no software license.
• Quick to maintain. One entry per transaction takes seconds. For a low-volume business a weekly update takes minutes.
• Useful for tax preparation. A well-kept cash book shows income and deductible expenses by category, which is the core of a simple small-business return.
• Matches cash-basis reporting. If money only moves when a sale or purchase happens, the cash book reflects the real position without adjustments.

Disadvantages of single-entry bookkeeping

• No error detection. Double-entry bookkeeping has a built-in check, because debits must equal credits. Single entry has no equivalent, so a mistyped amount can stay in the books indefinitely.
• No balance sheet. Without accounts for assets and liabilities, you cannot say what the business owns, owes or is worth.
• Limited insight. A cash book shows cash movement. It does not show which products are profitable or where margin is lost.
• Not suited to GAAP. Financial statements prepared under US GAAP use accrual accounting, as the OpenStax accounting text explains, which a single-entry cash book cannot support.
• Hard to scale. As transaction volume grows, a cash book becomes harder to keep accurate and easier to break.
• Higher fraud risk. Without the cross-checks of double entry, records are easier to alter without anyone noticing, which matters once more than one person handles money.

Single entry vs double entry bookkeeping

For a worked comparison of the same transactions in both systems, including the trial balance, see our single-entry vs double-entry guide.

Single entry and the IRS cash method are not the same thing

A common belief is that a business may keep single-entry books until it reaches some revenue figure. There is no such rule. What the IRS sets is a test for the accounting method, cash or accrual, which is a separate question from single or double entry.

Under section 448(c), a corporation or partnership meets the gross receipts test if its average annual gross receipts for the prior three tax years do not exceed $32 million, for tax years beginning in 2026. Businesses that meet the test can generally use the cash method and, as Publication 538 explains, can choose not to keep a formal inventory for tax, though they must still use a method that clearly reflects income.

So a business can be allowed to file on a cash basis while still needing double-entry books to run properly. Most do, long before the gross receipts test becomes relevant.

When to move beyond single-entry bookkeeping

Single-entry bookkeeping works until it does not, and the point is usually clearer in hindsight. These are the signals:

1. You are seeking a loan or investment. A lender or investor will ask for a balance sheet and income statement, which single-entry records cannot produce without reconstruction.
2. You hold inventory or fixed assets. Stock, equipment and their depreciation cannot be tracked in a cash book.
3. You extend credit or take it. If customers pay on terms or you owe suppliers, you need accounts receivable and accounts payable.
4. You have hired staff or taken on a partner. More people touching the money means you need the controls double entry provides.
5. You sell through several channels. Shopify, Amazon and wholesale payouts net off fees, refunds and reserves, and a cash book cannot separate them.
6. You cannot answer basic questions quickly. If working out last quarter’s margin takes a weekend, the records have stopped doing their job.

How to move from single entry to double entry

The switch is a one-off project: pick a start date, build a chart of accounts, set opening balances for every asset, liability and equity account, then record everything from that date in accounting software that posts both sides of each entry. The step-by-step switch is set out in our comparison guide.

How Atidiv helps businesses set up and keep the right bookkeeping system

Choosing the method is the first step. Keeping the books accurate month after month, as the business grows, is where most small and growing businesses struggle.

Atidiv’s bookkeeping services for small business cover both parts. When a business moves from a cash book to double entry, our team defines the chart of accounts, integrates the software stack and takes over daily transaction processing. After that we reconcile bank, card and loan accounts every month, prepare financial statements and dashboards, and run each month through a three-stage quality check. Contact us to talk about your setup.

Frequently asked questions

What is single entry accounting?

Single entry accounting is a bookkeeping method that records each transaction once, as income or an expense, in a cash book with a running balance. It shows cash in and out but does not track assets, liabilities or equity.

Is single-entry bookkeeping legal?

Yes. In the US the IRS describes the single-entry system in Publication 583 as simple and practical for a small business that is starting out. What the IRS requires is records that clearly show your income and expenses. Lenders, investors and auditors will usually expect double-entry financial statements.

Can I use single-entry bookkeeping for tax purposes?

For many small businesses filing on a cash basis, a well-kept cash book with categories and supporting receipts is enough to prepare a return. As the business grows, or if it holds inventory, you will need more structured records.

What is an example of single-entry bookkeeping?

A freelancer’s spreadsheet that lists each client payment and each business expense on its own row, with a running balance, is single-entry bookkeeping. The monthly totals by category give the income and expense figures for the tax return.

Can single-entry bookkeeping produce a profit and loss statement?

It can produce a simple income-minus-expenses summary. It will not reflect unpaid invoices, unpaid bills, depreciation or inventory, so it is a cash summary rather than a true profit and loss statement.

What software supports single-entry bookkeeping?

A spreadsheet such as Google Sheets or Microsoft Excel is enough. Accounting software such as QuickBooks, Xero or FreshBooks is built around double entry and is the better choice once you are ready to move beyond a cash book.

When should I switch from single to double entry bookkeeping?

Switch when you seek a loan or investment, hold inventory or fixed assets, extend or receive credit, hire staff or take on a partner, or sell through more than one channel. At that point the limits of single entry cost more than its simplicity saves.