Gather the original tax return, all supporting documents, and any new or corrected information
Obtain the correct amended return form for your tax year and country or tax authority
Complete the amended return with the corrected figures
Include any schedules, forms, or attachments that changed
Explain the reason for the amendment on the form if required
Recalculate your tax, refund, or balance due
Sign and date the amended return if required
File the amended return by mail or through the tax authority’s online system if available
Pay any additional tax owed by the deadline
Keep copies of the amended return and all supporting records
Track the status of the amended return after filing
Respond promptly to any notices or requests from the tax authority