Official form guide
Form CA4
Form CA4 is a corporation tax return form issued by the Revenue Commissioners for companies in Ireland. It is used to report taxable profits and calculate corporation tax liabilities for accounting periods.
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Form Overview
Revenue Commissioners - Form CA4
Form CA4 is a corporation tax return form issued by the Revenue Commissioners for companies in Ireland. It is used to report taxable profits and calculate corporation tax liabilities for accounting periods.
Risk Radar
Scan points- 1The most common mistake is miscalculating taxable profits by including non-deductible expenses.
- 2Incorrect calculation of taxable profits
- 3Missing allowable deductions
- 4Late submission leading to penalties
- 5Incomplete information about business activities
Plain English
This is the main tax form for companies in Ireland. If your business is registered as a company with Revenue, you'll likely need to complete this form once a year to report your profits and pay the correct amount of corporation tax.
Submission Date
- Filing date: Form CA4 must generally be filed within 9 months of the end of your company's accounting period. Late submissions may incur penalties and interest charges.
- Preparation window: collect IDs, supporting records, and signatures in advance.
- Final review: verify names, dates, and required fields before submission.
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What this form is for
- Use this form if your company is registered for corporation tax in Ireland
- Complete this form annually for each accounting period
- Use this form when reporting profits and calculating corporation tax liability
- Use this form when claiming certain corporation tax reliefs or exemptions
- Do not use this form for income tax returns (Form 11) or VAT returns (Form VAT 3)
Form selector
Use this form or another form?
Company with accounting period ending December 31
Standard annual corporation tax return
✓ Confirm your company's tax status with Revenue
Newly incorporated company
Initial registration and first tax return
✓ Check if special provisions apply to your first accounting period
Company with losses to carry forward
Reporting losses for future offset
✓ Ensure proper documentation of loss calculations
Form CA4 with additional schedules
Company claiming capital allowances
Claiming deductions for capital expenditure
✓ Maintain detailed records of qualifying assets
Form CA4 with capital allowances schedule
Non-resident company with Irish operations
Reporting Irish-sourced income
✓ Confirm your tax residency status with Revenue
Form CA4 with additional declarations
Deadline or filing window
Form CA4 must generally be filed within 9 months of the end of your company's accounting period. Late submissions may incur penalties and interest charges.
Before you submit
- 1Verify all financial figures match your company's accounts
- 2Check that all required sections are completed
- 3Confirm that calculations are accurate
- 4Ensure all necessary supporting documents are attached
- 5Check that the form is signed by an authorized person
- 6Verify the company registration number is correct
- 7Check that the accounting period dates are accurate
- 8Ensure contact information is up to date
How to file this form
- 1Gather all financial statements and tax documentation
- 2Complete the form with accurate financial information
- 3Calculate corporation tax liability based on current rates
- 4Submit through Revenue Online Service (ROS) if possible
- 5Keep a copy of the submitted form for your records
- 6Monitor for any correspondence from Revenue
- 7Follow up if you don't receive an acknowledgment within a reasonable time
Known limitations
- 1Form CA4 may not cover all types of corporation tax reliefs
- 2Complex group structures may require additional forms
- 3The form may not cover international tax reporting requirements
- 4Certain industries may have specific reporting requirements not covered in this form
- 5The form may not address recent changes in tax legislation until updated versions are released
Field map
Compact field-by-field guide
Identity
3 items
Your full name as Revenue holds it.
Your Personal Public Service number — Revenue matches the form to your record with this.
Your current address, including Eircode.
Details
1 items
The year or period the form relates to.
Amounts
1 items
Enter each amount against the heading it belongs to.
Declaration
1 items
Sign to confirm the details are correct and complete.
Almost done reviewing the fields?
Fillable formOpen in Editor->Form CA4 is currently the standard corporation tax return for Irish companies, though specific requirements may change with annual budgets or tax legislation updates.
What changed or needs a fresh check
- Check that you're using the current version of Form CA4
- Verify that the form includes the latest tax rates and thresholds
- Confirm that any new corporation tax reliefs are applicable
- Ensure that reporting requirements haven't changed
- Check if digital filing through ROS has any new requirements
Quick Facts
Downloads & source
Sources
- SRCForm CA4 is issued by the Revenue Commissioners
- SRCThe form is used for corporation tax reporting in Ireland
- SRCSubmissions are typically made through Revenue Online Service (ROS)
- SRCThe standard deadline is within 9 months of the accounting period end
- SRCNot confirmed in official source: specific sections included in the form
- SRCNot confirmed in official source: current tax rates applicable to the form
- SRCNot confirmed in official source: penalties for late submission
- SRCNot confirmed in official source: recent changes to the form requirements
Common confusion points
Distinguishing between accounting profits and taxable profits
Understanding which expenses are deductible for corporation tax
Determining the correct accounting period for filing purposes
Knowing when to include capital allowances in calculations
Understanding the difference between provisional and final tax payments
Determining if corporation tax installments are required
Understanding how losses can be carried forward or back
Knowing when professional advice is needed for complex situations
Source transparency
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