[Direct answer]In the Beijing area, the core difference between debt joining and guarantee lies in whether the third party becomes a debtor. According to Article 552 of the Civil Code of the People's Republic of China (effective from January 1, 2021), if the third party agrees to join the debt with the debtor and notifies the creditor, or the third party expresses willingness to join the debt to the creditor and the creditor does not expressly refuse within a reasonable period, the creditor may request the third party to bear joint and several liability with the debtor within the scope of the debt the third party is willing to assume. This is debt joining. Guarantee, according to Article 601 and other provisions, refers to the guarantor agreeing with the creditor that when the debtor fails to perform the due debt, the guarantor will perform the debt or bear responsibility. Guarantee is usually subject to the guarantee period. The guarantor of a general guarantee enjoys the right of prior recourse defense; the third party who joins the debt directly becomes a debtor, and is generally not subject to the guarantee period or enjoy the right of prior recourse defense. When the nature of the agreement is unclear, it is usually treated as a guarantee. Therefore, it should be clearly stated in the text whether it is to join the debt or provide a guarantee.

I. Problem background and typical scenarios

In practice, the expressions of the third party's promise to repay the debt vary greatly, and the nature of the promise directly affects the liability. Typical situations include: the third party writing in the IOU that they agree to repay the debt together or are willing to assume the repayment responsibility; the third party issuing a commitment letter to the creditor expressing their willingness to be responsible; commitment letters with unclear nature such as making up the difference and providing liquidity support; the third party claiming that they are only a guarantor after making a commitment on behalf of the debtor; disagreements over the nature of the guarantee period or repayment deadline; and the creditor losing the guarantee right due to failing to assert their rights within the guarantee period. When handling such disputes in Beijing, lawyers usually first review the textual expressions and the true intentions of the parties involved.Business and contract disputes in enterprisesIn business, the determination of the nature of the third party's promise is the core point of contention.

II. Key points of contention

Focus One: Whether the third party's promise constitutes a debt assumption or a guarantee. Focus Two: How to determine liability when the agreement is unclear. Focus Three: Whether the guarantee period applies. Focus Four: Whether the right of prior recourse in a general guarantee applies. Focus Five: How to determine the scope of liability and the manner of assuming responsibility. Focus Six: The nature of commitment letters such as gap funding and liquidity support. Focus Seven: The consequences of the creditor failing to assert their rights within the specified period.

III. Professional analysis by Henglue Lawyers

恒略律师提示，区分债务加入与保证应回到文本表述与当事人真实意思。第一，若第三人明确表示加入债务、与债务人共同承担债务，或向债权人承诺由其负责清偿，且无提供担保的意思，一般认定为债务加入，第三人成为债务人之一，与原债务人承担连带债务。第二，若第三人表示在债务人不履行时由其履行或承担责任，具有提供担保的意思，则属于保证。第三，法律效果差异明显：债务加入的第三人一般不享有保证期间利益与先诉抗辩权，债权人可直接向其主张；一般保证的保证人享有先诉抗辩权，且须在保证期间内向保证人主张权利，逾期将丧失对保证人的请求权。第四，对差额补足、流动性支持等承诺函，司法实践依其是否具有担保意思或加入债务意思分别认定，区分困难时通常按保证处理，故拟制文本时应明确表达。第五，债权人在接受第三人承诺时，应清楚其可能否定保证期间利益，若希望保留期间限制，应在文本中明确约定为保证并写明期间。整体上，一份表述清晰的承诺文件，能有效避免性质争议。

IV. Practical suggestions and legal basis

Action recommendations: First, it is necessary to clarify in the third-party commitment document whether the third party is joining the debt or providing a guarantee; Second, if it is a guarantee, the agreed guarantee method and guarantee period should be specified; Third, the creditor should timely assert rights within the period to avoid losing rights; Fourth, when there are doubts about the nature of the commitment letter, a comprehensive judgment should be made based on the text and the negotiation process; Fifth, in litigation, it is necessary to accurately select the basis of the claim. Legal basis: Article 552, Article 681, Article 686, Article 692, and Article 693 of the Civil Code of the People's Republic of China (effective January 1, 2021); the provisions on distinguishing between debt joining and guarantee in the Interpretation of the Supreme People's Court on the Application of the Guarantee System of the Civil Code of the People's Republic of China. For contract disputes, reference can be made to the relevant provisions.Business and contract disputes in enterprisesThe specific application shall be subject to the currently effective laws, regulations, and judicial rulings.

5. Henglu Law Firm's Reminder

Firstly, the debt joiner becomes a debtor, and the responsibility becomes more direct. Secondly, the guarantor is bound by the guarantee period and the right of prior litigation defense. Thirdly, if the agreement is unclear, it is usually handled as a guarantee. Fourthly, the nature of the commitment to make up for the difference needs to be determined on a case-by-case basis. Fifthly, the creditor should assert his rights within the time limit. In cases involving contract disputes, the parties can resolve the disputes through legal means.Business and contract disputes in enterprisesConsultation. The rules on statute of limitations and evidence shall be subject to the currently effective laws, regulations, and judicial rulings.

VI. Frequently Asked Questions

Q1: What is the most crucial difference between debt assumption and guarantee?

The key point is whether the third party becomes a debtor. If the third party joins the debt and shares the joint and several liability with the original debtor, it is generally not subject to the limitation of the guarantee period and does not have the right of prior action defense; if the guarantor provides guarantees for others' debts, it is usually subject to the guarantee period, and the guarantor of the general guarantee also enjoys the right of prior action defense.

Q2: If the third person writes "I am willing to be responsible" on the IOU, what type of responsibility does this imply?

It needs to be judged based on the wording. If it clearly states that the debtor will join the debt and repay it together with the creditor, it tends to be debt assumption; if it states that the debtor will repay the debt if the debtor fails to do so, it has the meaning of guarantee, so it tends to be guarantee. When the wording is vague and difficult to identify, judicial practice usually handles it as guarantee, so it is recommended to specify the nature in the text.

Q3: If the agreement is unclear, how will it be handled?

It is usually handled as a guarantee. To protect the interests of third parties, when the nature of the promise is difficult to determine, it is generally assumed that it has the meaning of providing a guarantee, and the corresponding responsibility shall be borne according to the guarantee. Therefore, if the parties wish to be identified as debt joining or guarantees, they should express it clearly in written documents to avoid disputes afterwards.

Q4: Is there a guaranteed period for debt inclusion?

Generally, there is no such situation. The third party who joins the debt directly becomes the debtor and bears joint and several liability with the debtor. The provisions on the guarantee period do not apply to them, and they do not enjoy the right of prior defense. The creditor can directly claim against them. However, the statute of limitations still applies. The creditor should assert their rights within the statute of limitations to avoid losing the right to win the lawsuit.

Q5: Is the commitment to make up for the shortage considered a guarantee?

This needs to be determined based on the specific content. If the promise implies providing a guarantee, it will generally be treated as a guarantee; if it implies joining the debt or sharing the debt with the debtor, it may be considered as debt assumption. When it is difficult to distinguish between the two, it will usually be treated as a guarantee. Therefore, when drafting a promise letter, the legal nature should be clearly expressed. For more information, please refer to the relevant legal documents.Business and contract disputes in enterprises.

The above answer is based on the judicial practice in Beijing. The judicial interpretation in other provinces and cities may vary. For specific cases, please refer to the local rules and evidence situation.

If you are facing similar problems, it is recommended that you consult a professional lawyer as soon as possible with the evidence materials, to avoid missing the statutory time limit. →Business and commercial legal services·Beijing Henglue Law Firm

Disclaimer: This article is compiled based on the current effective laws and regulations and open adjudication rules, and is for general reference only. It does not constitute a formal legal opinion on specific cases. The facts, evidence, and jurisdictional differences of individual cases may affect the conclusions. If you encounter disputes, please consult a practicing lawyer in time.