That number is the tax registration number of the IRS. The company will get a tax registration number after tax registration.

This stamp was carved in a small shop outside. When handling the qualification of receiving and purchasing invoices in the tax bureau, you should bring a copy of tax registration certificate, a copy of business license, official seal, financial seal or special invoice ticket, and the seal of legal representative. Agents who want to buy invoices should also bring the original ID card and a copy when applying, because the copy will be left by the tax bureau. Pay attention to the person who must buy the invoice, because if you need to bring your ID card in the future, you can't buy the first invoice until the fifth working day after filling out the form and checking it at the window.

I just finished it the day before yesterday.