Common Xero Setup Mistakes for Contractors to Avoid
Updated: 4 days ago
Why Your Xero Setup Matters More Than You Think
A Xero file set up on the fly in your first busy year is not a neutral mistake. It shapes every BAS you lodge, every margin you quote and every loan application you sign.
Watch Out The most expensive error is a chart of accounts built for a shop, not a job. It hides your true job costs until year end, when there is nothing left to fix.
Mistake 1: Skipping Conversion Balances and Opening Balances when moving to Xero
Conversion balances are the account balances you enter on the day you move across. Skip them, and every report you run from that day forward is wrong. Contractors often set a conversion date, enter a few bank balances, and start coding, leaving loans, work in progress and retention accounts at zero.
Here is how to get it right:
Pick a conversion date that matches a natural break, such as the end of a month or quarter.
Pull a balance sheet from your old system on that exact date.
Enter every balance, including loans, asset finance and retention held.
Reconcile each bank account to its statement before you code a single transaction.
Compare your first Xero balance sheet against the old one. They should match.
Mistake 2: A Xero Chart of Accounts for Construction That Doesn't Match How You Work
A Xero chart of accounts for construction should mirror how you quote and run jobs, not a generic template. Otherwise your profit and loss statement tells you nothing useful about where the money went.
Cost of Sales vs Expenses: Getting the Split Right
This is the split most trade files get wrong: direct costs belong in cost of sales, everything else in expenses.
Cost of sales: materials, subcontractors, hire equipment, site labour
Expenses: office rent, admin wages, insurance, software, vehicle running costs
Mistake 3: Ignoring Xero Tracking Categories for Trade Businesses
Xero tracking categories for trade businesses are the most useful feature contractors ignore. They let you tag every transaction to a job, crew or region, then report on each one, answering the only question that matters at the end of a job: did this project actually make money?
Tracking Categories vs Projects: Which One Fits Your Jobs?
Use tracking categories for ongoing groupings, and projects for one-off jobs with a start and end date.
Feature | Best For | Example |
Tracking categories | Ongoing reporting | Region, crew, trade type |
Projects | One-off jobs | A single build or fit-out |
Both together | Full job costing | Region + specific job |
Setting Up Tracking Categories for Project Profitability
Most contractors set up tracking categories and never use them consistently. Make tagging part of the workflow, not an afterthought.
A practical setup for a trade business:
Tracking Category 1, Job or Site. Name it after the job number or site address. Every material purchase, subcontractor invoice and hire cost gets tagged here.
Tracking Category 2, Cost Type or Crew. Use this to separate labour, materials, subcontractors and equipment hire within each job.
Make both mandatory. In Xero, you can set a tracking category as required on invoices and bills. This stops untagged transactions slipping through.
Mobile Receipt Capture and On-Site Tagging
This is where most contractor setups fall apart: receipts pile up in the ute, get entered weeks later, and the tracking category is wrong or missing.
Photograph a receipt on site and attach it to a transaction immediately
Code the expense to the right account and tracking category before you leave the job
Submit the claim for approval if someone else manages the books
Pro Tip Set up your tracking categories before you enter a single transaction. Retrofitting them later means re-coding months of history by hand, and if you have been running jobs without tags, you cannot reconstruct job profitability after the fact.
The Reporting Payoff
With tracking categories running properly, three reports change how you run the business:
Profit and Loss by Tracking Category, shows which jobs, crews or regions are profitable
Project Summary, shows margin per project, including labour and materials
Tracking Category Summary, shows total spend per category, useful for spotting a job that is running over before it finishes
Mistake 4: Getting Managing Subcontractor Payments in Xero Wrong
Managing subcontractor payments in Xero comes down to one rule: every subcontractor needs their own supplier record, and every payment needs a tax code and a payment summary.
Fix it like this:
Create a supplier record for each subcontractor
Ask for a tax invoice before you pay, every time
Code the payment to cost of sales, not expenses
Keep a separate account for subcontractor retention if you hold any
Mistake 5: Bank Feeds, GST Settings and Invoice Reminders Left on Default
Bank feeds, GST settings and invoice reminders are three defaults that quietly cost contractors money. Each takes minutes to fix.
GST Reporting and Tax Rate Traps
The most common GST trap is a tax rate left on the wrong setting for a transaction, a deposit coded as GST-free, or a private expense coded as GST on expenses. Both distort your BAS. Run the GST reconciliation report in Xero before every BAS; it takes five minutes and catches most coding errors before they reach the ATO.
Key Takeaway Before you lodge any BAS, run the GST reconciliation report. If it does not balance, do not lodge. Find the error first.
Mistake 6: Leaving User Permissions Wide Open
Everyone with access to your Xero file should have the lowest permission level they need. Most contractors give everyone "standard" access and never revisit it. That creates two problems: a staff member or former employee can see your full financial position, and if something goes wrong you have no audit trail showing who did what.
Fix it in an afternoon:
Set yourself as the only adviser-level user
Give bookkeepers "adviser" access only if they need it
Give admin staff "standard" access, no more
Remove access the day someone leaves
Review the user list every quarter
Mistake 7: Migrating Data Without a Plan
Data migration is where most Xero files get permanently damaged. Contractors move across mid-year, import transactions with the wrong dates, and end up with a file that never quite reconciles. The damage shows up months later when a BAS does not match the bank, or a job that looked profitable has costs sitting in the wrong period.
Xero's official guidance on importing data safely
The Conversion Date Trap
The biggest migration mistake is converting mid-month or mid-job. Move across on the 15th and you have half a month of transactions in each system, painful to reconcile, and your monthly reports will never line up.
Pick a conversion date that matches a natural break:
End of a month, quarter or financial year
End of a BAS period, so GST reporting stays clean
A point where no major job is mid-invoice
What to Import and What to Leave Behind
Not everything should come across. Contractors who migrate badly often import years of historical transactions Xero does not need.
A cleaner approach:
Bring across: opening balances (as a single journal), outstanding debtors and creditors, asset and loan balances, retention held and retention payable
Leave behind: every historical transaction already reconciled in the old system. Keep the old file read-only for at least five years, the ATO requires records to be kept for five years from the date you lodge your tax return.
Never import: bank transactions that have already been reconciled elsewhere. This creates duplicates that are almost impossible to untangle.
Retention and Work in Progress
Retention is the migration item contractors most often forget. If you hold retention on completed jobs, or owe retention to subcontractors, those balances must be entered as opening balances in Xero. Skip them and your balance sheet is wrong from day one, and job profitability reports overstate margin on every job with retention.
Bank Feeds and the First Reconciliation
Before you code a single transaction in Xero:
Connect every bank account, credit card and loan account
Enter the opening balance for each account as at the conversion date
Reconcile each account to its statement
Only then start coding transactions
If a bank account does not reconcile to zero at the conversion date, stop. Find the discrepancy before you go further. Fixing it later means unpicking every transaction that followed.
A Migration Checklist
Convert at a clean date, not mid-month
Never import transactions you have already reconciled in your old system
Enter opening balances as a single journal, not as individual transactions
Include retention held, retention payable and work in progress
Reconcile every bank account to zero before you start coding
Keep your old system read-only for at least five years
Run a balance sheet in Xero on day one and compare it to the old system, they should match
If your last provider set up Xero wrong and you are still untangling it, you are not alone.
Pro Tip Before you cancel your old accounting software, export every report to PDF. You will need them for at least five years, and some providers delete access once the subscription ends.
Frequently Asked Questions
Why is my Xero bank reconciliation not matching my actual bank balance?
The usual cause is a setup error rather than a bank error. Check for duplicate bank feeds, transactions dated before your conversion date, or opening balances that were entered as a single journal instead of transaction-by-transaction. In Xero, your bank reconciliation should match the bank statement line by line. If it doesn't, reconcile from your conversion date forward and correct any duplicated or missing entries before touching GST reporting.
Should contractors use tracking categories or projects in Xero?
It depends on how you quote and report. Tracking categories for trade businesses suit simple splits like job type or location, and they work well for profit and loss reporting by category. Projects handle job costing with time, expenses and invoices tied to one job. Many contractors use both: a tracking category for the broad split and projects for individual jobs. Decide before you enter transactions, because changing this later means re-coding everything.
What is the Xero code for subcontractor payments?
There is no single universal code. Most contractors map subcontractor payments to a dedicated account under cost of sales, such as 'Subcontractors', so job margins stay accurate. The account code number itself is your choice; what matters is that it sits in the right section of your chart of accounts and that you collect a Tax File Number declaration and ABN from each subcontractor. Without an ABN, withholding may apply.
How do I correctly track project profitability in Xero?
Set up projects before you start entering costs. Allocate every supplier bill, subcontractor invoice and timesheet to the correct project, then run the project profit and loss report. The biggest mistake is mixing job costs into general expenses, which hides which jobs actually made money. If you quote fixed price work, review project reports weekly rather than at year end, when it is too late to adjust.
Why Choose Tropic Books & Finance?
Tropic Books & Finance is focused on delivering practical bookkeeping & finance solutions backed by personalised service to:
Electricians and Sparkies
Carpenters and Chippies
Plumbers
Concreters
Landscapers
HVAC Contractors and Fridgies
Tilers
Roofers
Glaziers
Plasterers
Painters
Civil and Earthmoving Contractors
Simon Smyth
Phone: 0427 216 011
Email: simon@tropicbooks.com.au
Comments