Xero Account Mapping for CT600

If you use Xero to manage your company's finances, preparing your company tax return requires one important step that many directors miss: your Xero accounts do not map directly onto CT600 boxes. You need to understand how Xero's chart of accounts structure relates to your tax computation — and make a handful of critical adjustments — before your figures are ready to file.

This guide explains how to map Xero accounts to your CT600, which adjustments are mandatory, how to export your trial balance, and the common mistakes that cause errors on submission.

How Xero Organises Its Chart of Accounts

Xero uses a chart of accounts with numbered account codes, grouped into categories:

Category	Xero Account Type	Typical Codes	Purpose
Revenue	Revenue	200–299	Sales and income
Cost of Sales	Direct Costs	300–399	Materials and direct labour
Operating Expenses	Overheads	400–499	Rent, utilities, salaries
Fixed Assets	Fixed Assets	700–739	Equipment, vehicles
Current Assets	Current Assets	740–799	Debtors, bank, stock
Liabilities	Current/Non-current Liabilities	800–899	Creditors, loans
Equity	Equity	900–999	Share capital, retained earnings

Note that Xero allows you to customise account codes, so your chart of accounts may differ from the defaults above. When mapping to the CT600, what matters is the function of each account, not its specific code number.

What the CT600 Needs from Your Xero Data

The CT600 reports your company's profit chargeable to corporation tax. This starts with your accounting profit — turnover minus all expenses as shown in your Xero profit and loss report — and is then adjusted for tax-specific items:

• Disallowable expenses: items in your accounts that HMRC does not allow as a tax deduction (depreciation being the most significant)
• Capital allowances: the HMRC-approved deduction that replaces depreciation
• Other adjustments: accruals, loan relationship income and expenses, and timing differences

Your Xero profit and loss report provides the accounting profit as the starting point. The CT600 adjustments are made on top.

For a full explanation of the key CT600 boxes and what they contain, see our CT600 boxes explained guide.

Key Xero Account Mappings for Your CT600

Turnover

Map all Xero Revenue accounts to your turnover figure. This includes:

• Sales of goods
• Service income
• Rental income from trade activities
• Other trading income

Do not include:

• Bank interest received (reported separately in the loan relationships section)
• Dividend income received (reported under investment income)
• Capital gains from asset disposals (reported in a separate CT600 section)

Allowable Trading Expenses

Most of your Xero Direct Costs and Overhead accounts will be allowable. Common mappings:

Xero Account	CT600 Treatment
Cost of goods sold	Allowable
Salaries and wages	Allowable
Employer National Insurance	Allowable
Rent and business rates	Allowable
Software subscriptions	Allowable
Business travel	Allowable
Professional fees	Allowable
Depreciation	Disallowable — add back
Client entertainment	Disallowable — add back
Fines and penalties	Disallowable — add back
Personal expenses	Disallowable — add back

Depreciation: The Most Important Adjustment

Xero automatically posts a depreciation charge for fixed assets using the rates you configure in the fixed assets module. This depreciation appears as an expense in your Xero profit and loss, which reduces your accounting profit.

For corporation tax purposes, depreciation is not allowable. You must:

1. Add back the full depreciation charge from your Xero accounts
2. Claim capital allowances instead — these are the HMRC-approved deductions based on the actual cost of your assets and the applicable pool rates

Failure to add back depreciation is one of the most common errors in small company CT600 returns. It understates your tax profit and can lead to an HMRC enquiry.

For a full guide on calculating capital allowances correctly and which pool rates apply to different asset types, see our capital allowances CT600 guide.

Fixed Assets: Using Xero's Asset Register

Xero maintains a fixed asset register showing each asset's original cost, accumulated depreciation, and net book value. When preparing your CT600 computation, you need the original cost of assets acquired during the period — not the net book value after depreciation.

To access this in Xero: go to Accounting > Fixed Assets. You can view or export a list of all assets, their cost, and the date they were acquired. This is your starting point for calculating Annual Investment Allowance (AIA) and writing down allowance (WDA) claims.

Loan Relationships: Bank Interest and Finance Costs

Bank interest received appears in Xero as non-trading income. For CT600 purposes, bank interest and most finance income is reported under loan relationships — typically in the CT600 boxes for non-trading loan relationship credits and debits (boxes around the 170–195 range).

Bank interest paid on business loans is an allowable deduction but is also reported through loan relationships, not as a trading expense. If your Xero accounts include significant interest income or expense, ensure it is allocated to the correct section of your CT600 and not mixed into trading profit.

Directors' Loan Accounts

Xero tracks directors' loan accounts as a current liability (if the company owes the director) or a current asset (if the director owes the company). If a director's loan account is overdrawn at the accounting period end — meaning the director owes the company money — this can trigger an additional tax charge known as a Section 455 charge.

See our directors loan CT600 guide for full details on how to report and manage this.

Exporting Your Trial Balance from Xero

The most reliable method for transferring Xero data to your CT600 is via a trial balance export.

Steps to export from Xero:

1. Go to Accounting > Reports > Trial Balance
2. Set the date to your accounting period end date
3. Check that all year-end journals have been posted (accruals, prepayments, stock adjustments)
4. Select Accruals basis for limited companies (not cash basis)
5. Export to CSV, or note the figures directly

The trial balance shows the closing balance of every account — income, expenses, assets, and liabilities. A balanced trial balance (total debits equal total credits) confirms that your Xero data is complete and consistent.

Importing into your CT600:

If you are filing your CT600 using online software that accepts trial balance imports, you can upload your Xero trial balance directly rather than entering each figure manually. The software maps the Xero account types to the appropriate CT600 boxes, significantly reducing the risk of data entry errors.

For a full walkthrough of the CT600 filing process, see our how to file your company tax return guide.

Common Xero Mapping Mistakes

Not adding back depreciation

As covered above, Xero's depreciation charge must be added back in your tax computation. This is the single most common mistake when mapping Xero data to a CT600. Always check your computation includes a depreciation add-back line.

Using VAT-inclusive figures

Xero can display report figures including or excluding VAT depending on your settings and the VAT scheme you use. Your CT600 must use net of VAT (ex-VAT) figures throughout. Verify that your Xero profit and loss and trial balance reports are displaying net amounts before transferring them to your tax computation.

Mixing personal and business transactions

Xero bank feeds sometimes pull in personal transactions that have been miscoded to business expense accounts. Before finalising your CT600, review your expense accounts for any personal items and reclassify them as director's drawings or ensure they are added back as disallowable.

Exporting before year-end journals are complete

Exporting your trial balance before all year-end adjustments are posted will give you incomplete figures. Ensure that accruals, prepayments, stock count adjustments, and any provisions are fully journalled in Xero before exporting your data.

Treating capital purchases as expenses

If a capital asset (equipment, vehicle, computer) has been posted to an expense account in Xero rather than a fixed asset account, it will appear as a trading expense and understate your profit. Conversely, if it is correctly recorded in fixed assets, it will not appear in trading expenses — and you claim capital allowances separately.

Review your Xero fixed asset register and ensure all qualifying assets are correctly classified.

Summary

Mapping Xero accounts to your CT600 is straightforward once you understand the key principles: your accounting profit from Xero is the starting point, depreciation must be added back and replaced with capital allowances, and certain income (bank interest, investment income) goes into specific CT600 sections rather than trading profit.

Always export your trial balance after all year-end journals are complete, use accruals basis figures, and verify that your amounts are net of VAT. For a step-by-step walkthrough of completing and submitting the CT600, see our company tax return filing guide.