The chart of accounts is the least glamorous decision in setting up a business and one of the most consequential. It determines what your reports can tell you, how much work your BAS takes, and whether your accountant spends June asking questions or preparing your return. Most businesses accept whatever the software suggested on day one and live with it for years.
What is a chart of accounts?
It is the list of categories that every transaction gets coded to, organised into five types: assets, liabilities, equity, income, and expenses. Income and expense accounts build your profit and loss statement; assets, liabilities, and equity build your balance sheet. When you code a supplier payment to "Motor Vehicle Expenses" you are choosing an account from this list, and the sum of those choices is what your financial reports actually are.
How many accounts should a small business have?
Enough to answer the questions you genuinely ask, and no more. Thirty to sixty active accounts suits most small businesses. The failure modes sit at both extremes. Too few, and a single "General Expenses" account absorbs a third of your spending, leaving you unable to see what is happening. Too many, and coding becomes inconsistent — if there are four plausible accounts for a hardware purchase, different people will pick differently and the same cost lands in different places month to month, which is worse than a slightly coarse structure applied consistently.
How should the accounts be structured?
Group them the way you think about the business. Separate income streams if you make decisions based on them — a café with a retail line, a trades business with service work and installations. Split direct costs from overheads so you can see a gross margin rather than just a bottom line. Keep expense accounts aligned with the categories you will need at tax time, so the year-end mapping is obvious. And use account numbering ranges consistently, leaving gaps between accounts so new ones can be inserted in the right place later instead of appearing at the bottom of a report.
How does GST fit in?
GST is not an account you code to manually — it is a tax rate applied to a transaction, which posts automatically to a GST control account. What matters is setting a sensible default tax rate on each account so the right treatment is applied without thinking. Bank interest, ASIC fees, wages, and most government charges are not subject to GST; if those accounts default to GST on Expenses, every entry overstates your claim until someone notices. Getting the defaults right at setup is what makes BAS preparation a review rather than a reconstruction.
What are the most common mistakes?
Creating a new account rather than looking for the existing one, so the file slowly accumulates near-duplicates. Mixing personal spending through business accounts instead of treating it as drawings or a loan account. Keeping every default account the software installed, including dozens irrelevant to your industry. Coding a full loan repayment to an expense account when only the interest portion is deductible and the principal reduces a liability. Recording asset purchases as expenses rather than to a fixed asset account where depreciation or an immediate write-off can be applied correctly. And treating the suspense account as permanent storage for anything unclear.
Can I restructure the chart of accounts later?
Yes, and sometimes you should — a business that has changed shape often outgrows the structure it started with. Do it at the start of a financial year so your comparatives stay meaningful. Where an account holds historical transactions, merge or archive it rather than deleting it, so prior-year reports still reconcile. And make the change once, deliberately, with a short internal note of what each account is for; a restructure nobody documents is undone within a quarter by whoever codes the next batch of bills.
How do you keep it working over time?
Review it annually alongside your EOFY preparation. Archive accounts nobody has used in twelve months. Look for expense lines that have grown large enough to deserve splitting out, and small ones worth consolidating. Restrict who can create new accounts — most coding inconsistency starts with a well-meaning person adding "Misc Supplies" at 4pm. A chart of accounts is not set-and-forget infrastructure; it is a small annual tidy that keeps every report downstream honest.
A well-built chart of accounts pays for itself every time you look at a report. The Metier Group sets up and reviews accounting files for Perth businesses through our bookkeeping services, including Xero setup and cleanups of files that have drifted. Contact us if your reports are not telling you what you need to know.