It doesn’t matter if you are too nervous. First, paste the torn invoice for tax certification. If the deduction copy cannot pass the certification, use the invoice copy to authenticate the deduction; if the invoice cannot pass the certification, You can contact your customer and it will be OK to void the invoice for that month and issue it again. If there is trouble every other month, you need to go to the tax bureau to apply for a red-letter invoice application form. Please consult the local tax bureau for specific circumstances.

Hope this helps you