Improving the value-added tax (VAT) credit chain is of great significance for optimizing the VAT system, reducing corporate tax burdens, and avoiding double taxation. Progress can be made in multiple aspects regarding the VAT on agricultural products and the overall credit mechanism: Further promote and optimize the pilot program for verifying and deducting input VAT on agricultural products, adopt scientific methods such as the input-output method, cost method, and reference method to calculate input VAT so that it aligns with the actual production and operation conditions of enterprises. At the same time, regularly update and adjust deduction standards to adapt to industrial development and technological progress, and gradually expand the scope of the pilot program based on the characteristics of local agricultural industries and tax collection and management conditions, incorporating more agricultural product processing industries into the program to address tax loopholes and unreasonable corporate tax burdens caused by issues related to credit certificates; In addition, strengthen the management of invoices for the sale and purchase of agricultural products, clarify their scope of issuance, requirements for issuance, and conditions for deduction to ensure the authenticity and legality of invoices. Meanwhile, specify that when general taxpayers obtain special VAT invoices for agricultural products issued by small-scale taxpayers, they can calculate the deduction based on the face value multiplied by the deduction rate, which is independent of the actual collection rate, further consolidating the foundation of the agricultural product VAT credit chain; For the improvement of the overall VAT credit chain, consideration can be given to including input VAT corresponding to the purchase of loan services in the scope of deduction, particularly to reduce the tax and capital costs for industries such as advanced manufacturing that have high capital demands. At the same time, further improve the VAT refund system for excess input credits, simplify the refund process, and enhance refund efficiency to ensure that taxpayers can receive timely refunds of excess input credits, thereby alleviating the pressure of capital occupation. Additionally, promote the coverage of the excess input credit refund policy to more industries and achieve full policy coverage, ultimately making the VAT credit chain more complete and effective.

In the value-added tax (VAT) credit mechanism, strengthening invoice management is a core link to ensure the integrity of the credit chain and prevent tax risks. It is necessary to build a closed-loop management system covering the entire process of invoice issuance, circulation, verification, and supervision, and specific progress can be made through the following multi-dimensional measures:  

First, standardize the source management of invoice issuance and clarify the invoice issuance rules for different entities. For example, require sellers to issue invoices truthfully in accordance with actual business operations, ensuring that invoice items (such as commodity name, quantity, amount, and tax rate) are consistent with real transactions. Especially for special scenarios such as agricultural product purchase invoices and special VAT invoices issued on behalf of small-scale taxpayers, refine the qualification review of invoice-issuing entities and the requirements for retaining invoice information (e.g., retaining purchase and sales contracts, farmers' identity certificates, and logistics documents for agricultural product purchases), so as to eliminate source problems such as "falsely issued invoices" and "invoices issued on behalf of others".  

Second, strengthen the verification mechanism in the invoice circulation link. Relying on the national VAT invoice verification platform, promote taxpayers to complete the verification of authenticity and information comparison in a timely manner after obtaining invoices, focusing on checking the consistency of key information such as invoice code, invoice number, and the taxpayer identification number of the buyer and seller. At the same time, require enterprises to establish an invoice recording and review system, taking the invoice verification result as a prerequisite for deducting input tax, so as to avoid the breakage of the credit chain caused by obtaining abnormal invoices (such as out-of-control invoices and cancelled invoices).  

Third, improve the full-life-cycle digital supervision of invoices. With the help of technologies such as big data and artificial intelligence, connect the data links between tax authorities, enterprises, financial institutions, and logistics platforms, and realize the "triple alignment" comparison of invoice information, capital flow (e.g., bank transfer records), and goods flow (e.g., logistics and transportation documents). Automatically issue early warnings for risky behaviors such as abnormal invoice issuance amounts, inconsistent business addresses of buyers and sellers, and frequent cancellation and re-issuance of invoices, so as to improve the accuracy of supervision.  

Fourth, improve the punishment and repair mechanism for irregular invoice issuance. Increase the penalty intensity for illegal acts such as falsely issuing invoices and forging invoices, incorporate such acts into the corporate tax credit rating system, and implement joint punishment (such as restricting invoice collection and prohibiting participation in government procurement). At the same time, clarify the handling process for abnormal invoices, allowing taxpayers to resume their qualification for deducting input tax in accordance with regulations after supplementing and providing legal supporting materials, so as to prevent the impairment of credit rights and interests due to non-subjective irregularities.  

Fifth, strengthen targeted measures for invoice management in special industries. For example, in fields with high credit risks such as agricultural products and bulk commodities, implement the "invoice + filing" management model, requiring enterprises to additionally retain supporting materials such as warehousing records and quality inspection reports for invoices related to large-value transactions. Conduct classified labeling management for invoices corresponding to differential taxation and tax-exempt items, clearly distinguishing between deductible and non-deductible scopes, so as to further plug credit loopholes and ensure that VAT invoices play the compliance and effectiveness of a "voucher hub" in the credit chain.