Most of the problems we fix in Xero weren't caused by the software. They were caused by the setup. A wrong GST reporting method, a bloated chart of accounts, missing conversion balances - these are the mistakes that quietly cost Australian businesses thousands of dollars in wasted time, incorrect BAS lodgements, and decisions made from bad data

We onboard new clients every month, and the first thing we do is review their Xero file. After hundreds of these reviews across trades, professional services, health, and manufacturing businesses, the same setup mistakes keep appearing. Some take an hour to fix. Others take weeks of untangling, especially when a full financial year of transactions has been coded to the wrong accounts or a BAS has been lodged on the wrong reporting basis

Here are the ones that actually cost money

Running with the default chart of accounts

Xero's onboarding wizard makes it easy to get started. Click through, accept the defaults, connect a bank feed, and you're accounting. The problem is that the default chart of accounts is generic. A plumbing business and a marketing agency get the same set of accounts

That matters because your chart of accounts determines what your reports actually tell you. If you've got one "Sales" account for a business that does three different types of work at different margins, your Profit and Loss report tells you almost nothing useful. You know you made money. You don't know where

We see this constantly with trades businesses. A construction company doing residential renovations, commercial fit-outs, and maintenance contracts will have wildly different margins on each. But if all revenue lands in one account, the owner has no idea which part of the business is carrying the other

The flip side is just as common - a chart of accounts with 80 expense categories when 25 would do the job. Every time someone codes a transaction they're choosing between "Office Supplies", "Stationery", "Printing", and "Computer Consumables". Nobody codes it consistently, the categories become meaningless, and the P&L is a wall of small numbers that nobody reads

The fix isn't complicated. Before you code a single transaction, sit down and think about what you want to measure. Set up income accounts that match your revenue streams. Set up expense accounts that group costs by how you manage them, not by what the receipt says. Our Xero guide covers the foundations in detail

Getting the GST reporting basis wrong

This one is expensive and surprisingly common

When you set up Xero in Australia, you choose whether to report GST on a cash basis or accrual basis. Cash means you report GST when money actually hits or leaves your bank account. Accrual means you report it when you raise an invoice or receive a bill, regardless of whether payment has happened. Most small businesses under $10 million turnover use cash basis. The Australian Taxation Office (ATO) lets you choose, but whatever you registered for needs to match what Xero is set to

If your Xero file is set to accrual but you're registered for cash reporting, every BAS you lodge will be wrong. You'll be reporting GST on invoices your customers haven't paid yet, and claiming credits on bills you haven't settled. The ATO won't catch it immediately, but when they do - or when your accountant does at tax time - you're looking at amended BAS lodgements and potential penalties

We picked up a client last year whose previous bookkeeper had set the basis incorrectly three years earlier. Every quarterly BAS for three years needed reviewing. The cost to fix it was more than the original Xero setup would have been if done properly

Check yours right now. Go to Accounting > Advanced > Financial Settings in Xero. Confirm the GST reporting basis matches what the ATO has on file for your business. If you're not sure what the ATO has, check your ABN registration at abr.business.gov.au or call them

Skipping conversion balances entirely

Every Xero file has a start date - the date from which transactions begin. If you've been operating for any length of time before setting up Xero, your business has a financial position at that date. Money in the bank, outstanding invoices customers owe you, bills you haven't paid, loan balances, equipment values. That snapshot is your conversion balance

Skipping it is one of the most common mistakes we see, and it creates problems that compound. Your bank balance in Xero won't match your actual bank balance. Your Balance Sheet will be wrong. Your accountant won't be able to prepare your tax return from Xero without significant manual adjustment, which costs you money in accounting fees every year

The other version of this mistake is entering conversion balances that don't balance. Debits need to equal credits. If they don't, Xero dumps the difference into a "Historical Adjustment" account, which is Xero's way of saying "something is wrong and I don't know what". We've seen Historical Adjustment balances over $200,000 sitting in files that nobody has questioned

We wrote a full guide to setting up conversion balances correctly because it's that common and that important

Bank feeds connected in the wrong order

There's a specific sequence to connecting bank feeds in Xero, and doing it out of order creates duplicate transactions that take hours to clean up

The correct order. First, add the bank account in Xero. Then activate the bank feed through your bank (Yodlee or direct feed, depending on who you bank with). Wait for transactions to start appearing. Then - and this is the step people skip - import the transactions that happened between your Xero start date and the day the feed went live. We call this "filling the gap"

What goes wrong. People connect the feed before importing historical transactions, then import the CSV from their bank. Now they have duplicate transactions for the overlap period. Or they import a CSV that starts before their conversion date, creating transactions that don't belong. Or they connect two feeds to the same account accidentally

The gap-filling step trips up even experienced bookkeepers. Our bank feeds guide walks through the process, including the Open Banking changes that have made direct feeds faster and more reliable in 2026

Not importing outstanding invoices and bills

Related to conversion balances, but worth calling out separately because people miss it so often

If customers owed you money at your Xero start date, those invoices need to exist in Xero. Same for any bills you hadn't paid. The conversion balance will show the total amounts in Accounts Receivable and Accounts Payable, but the individual invoices and bills need to be there too. Without them, your aged receivables report is blank, you can't track who owes what, and when payments arrive you can't match them to anything

The numbers tell the story. A $3 million revenue business might have $300,000 in outstanding receivables at any given time. If those invoices aren't in Xero, you're managing cash collection from memory or a spreadsheet while paying for accounting software that's supposed to handle it

Ignoring tracking categories

Tracking categories are one of the most underused features in Xero. You get two tracking categories with up to 100 options each. They let you slice your Profit and Loss by dimensions that don't fit in the chart of accounts - divisions, locations, projects, cost centres

A consulting firm with three practice areas can use one set of income and expense accounts but track revenue and costs by practice using a tracking category. Run a P&L filtered by "Advisory" and you see what that practice area actually earns. Without tracking, you'd need three sets of income accounts and three sets of expense accounts - a chart of accounts that's three times the size and three times the headache

One common misuse we see - using tracking categories for jobs. Xero allows up to 100 tracking options per category. If you're adding new jobs weekly, you'll hit that ceiling fast and end up with a useless list of 100 completed projects cluttering every dropdown. For job-level profitability, use Xero Projects or a dedicated job management tool like SimPro

Mixing personal and business transactions

This applies mostly to sole traders and partnerships, but we see it in company structures too

Connecting a personal credit card to Xero and then trying to tag which transactions are business and which are personal creates a reconciliation nightmare. Every personal Netflix subscription and grocery shop lands in your bank feed. Someone has to manually exclude each one. Multiply that by 52 weeks and it's hours of bookkeeping time you're paying for that produces zero value

Even as a sole trader where technically all income is yours, keep the banking separate. One business account, one business card. It costs almost nothing at most banks, and it halves the time your bookkeeper spends on reconciliation. That saving alone pays for a year of bank fees within the first BAS quarter

Setting it up and walking away

The final mistake isn't really a setup mistake - it's what happens after setup. Xero is configured once but the business changes continuously. New revenue streams appear. Staff numbers grow. You register for GST when you pass the $75,000 threshold. You switch from sole trader to company structure. Each of these changes needs to be reflected in Xero

We recommend reviewing your Xero configuration at least annually, ideally at the start of each financial year. Check whether your chart of accounts still reflects how the business operates. Check whether your tracking categories are still relevant. Check whether new Xero features - like JAX or the embedded Syft Analytics - could replace workarounds you've been using

And if you're migrating from MYOB or another platform, don't treat it as a straight lift-and-shift. It's a chance to fix everything on this list at once. Get the chart of accounts right. Get the conversion balances right. Connect the feeds in the right order. The cost of doing the migration properly is a fraction of the cost of fixing a bad setup twelve months later

Current as at March 2026