What is a cash book? And how to use one.

July 1, 2026
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A cash book is a simple way of keeping track of the money your organisation receives and spends.

At its most basic, a cash book is a record of the transactions in your bank account. If your organisation uses petty cash, it can also record the cash you receive and spend outside your bank account.

A cash book helps you do three important things:

  1. keep a record of money coming in and going out
  2. categorise your transactions
  3. check that your records match your actual bank balance

That last point is important. A good cash book should let you “balance” your bank account. In other words, if you start with your opening bank balance, add all the money received, and subtract all the money paid, the closing balance in your cash book should match the balance in your bank account.

In the old days, people might have called this “balancing the cheque book.” The same idea still applies today, even if your records are now kept in a spreadsheet or app.

Is a cash book the same as an accounting system?

Not quite.

A cash book is a simple record of cash received and cash paid. It is usually based on what has actually happened in your bank account.

An accounting system is usually more full-featured. It will often use double-entry accounting, which means every transaction is recorded in at least two places. This allows the system to track things like assets, liabilities, invoices, bills, money owed to you, and money you owe to others.

That makes accounting systems more powerful, but also more complex.

Cash books are usually much simpler. They are often useful for:

  • personal record keeping
  • small charities and non-profits
  • small clubs and societies
  • simple community projects
  • some sole traders or very small businesses

For many small organisations, especially those using cash-based reporting, a well-kept cash book may be enough.

Can a cash book be used for tax?

Sometimes, yes.

A cash book can help calculate tax obligations, such as GST returns or income tax, if the organisation’s tax situation is simple enough.

But as things get more complex, many organisations move to a full accounting system or work with an accountant. This is especially likely if the organisation has GST, payroll, invoices, assets, loans, multiple projects, or more complex reporting needs.

What does a cash book look like?

“Cash book” is a generic term. It does not refer to one specific product or format.

A cash book could be:

  • a physical book where you write down transactions by hand
  • a spreadsheet in Google Sheets or Microsoft Excel
  • an app that connects to your bank account and helps categorise your transactions

For example, Charities Services has an Excel-based Automated Cash Book for Tier 4 charities. Their current tool is designed to help smaller charities prepare their performance report by organising cash transactions into the right reporting categories.

Example: https://www.charities.govt.nz/reporting-standards/tier-4/automated-cash-book-helping-you-report-your-cash-transactions

A cash book app, such as the Good Numbers App, can do some of the same basic things as a spreadsheet cash book, but with extra support. For example, it may connect to your bank account, help categorise transactions, store receipts, and prepare reports.

Example: Meet the Good Numbers App

Example: https://www.prosaic.works/

What should a good cash book include?

A useful cash book should usually include:

  • the date of each transaction
  • a description of what the transaction was for
  • the amount received or paid
  • the bank account or cash account it relates to
  • a category for reporting
  • notes or references, if needed
  • the running or closing balance

For a small charity or non-profit, the categories should line up with the kind of reporting you need to do. For example, Tier 4 charities need to report cash received and cash paid using the categories required by the External Reporting Board (XRB) standard and Charities Services reporting process.

When is a cash book enough?

A cash book may be enough when your organisation has simple finances.

For example, it may work well if you:

  • mostly receive grants, donations, membership fees, or simple income
  • mostly pay ordinary expenses
  • do not issue many invoices
  • do not need detailed project accounting
  • report on a cash basis
  • mainly need to prepare simple annual financial reports

A cash book might not be enough if your organisation has more complex needs, such as payroll, GST, debtors and creditors, loans, assets, stock, multiple branches, or detailed management reporting.

The main idea

A cash book is not scary. It is just a clear record of money in and money out.

For small charities, clubs, societies, and community groups, a good cash book can be one of the most useful financial tools you have. It helps you know what happened, check your bank balance, keep better records, and prepare the information you need for reporting.

The important thing is not whether your cash book is a notebook, a spreadsheet, or an app. The important thing is that it is accurate, up to date, and organised in a way that helps you understand your money.

Disclaimer

This guide is general information only. It is designed to help small charities, clubs, societies, and community groups understand what a cash book is and how it might be used.

It is not accounting, tax, legal, or financial advice. Your organisation’s situation may be different depending on its size, structure, reporting tier, GST status, funding agreements, and other obligations.

If you are unsure what records your organisation needs to keep, whether a cash book is enough, or how to meet your reporting or tax obligations, you should get advice from an accountant, bookkeeper, tax adviser, lawyer, or the relevant government agency.

Good Numbers does not take responsibility for decisions made based on this guide.

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