1. Ask for payment voucher: ask the other company to provide payment vouchers, such as bank transfer records and telegraphic transfer vouchers, which can be used as the basis for confirming that the other party has paid, or as the voucher for posting.
2. Signing a contract: it is determined that the rights and interests of both parties and the payment responsibilities are clearly stipulated in the cooperative patent development contract, and the accounting method of the other party without invoicing is indicated in the contract.
3. Issue a receipt certificate: You can issue a receipt certificate yourself, record the specific amount and payment date on it, and ask the other party to confirm and sign.