1. Check for errors and adjustment amount: verify the deleted tax amount, calculate the correct amount, and collect documents and certificates related to tax adjustment, tax declaration, transaction records and invoices.

2. Contact the tax department: contact the tax department to explain the error in deleting the tax amount and consult the specific steps and required documents.

3. Submit the change declaration: fill in the change declaration form and submit the correct tax amount and relevant documents according to the requirements of the tax authorities.