[Direct answer]In the Beijing area, if there is an agreement on the payment deadline and the interest rate for overdue payments in the contract, the calculation period shall start from the day following the agreed payment date; if there is no such agreement, the calculation period shall start from the "due date" —— the date when the reasonable payment period determined according to the transaction practice expires after the delivery of the goods; if no interest is stated in the lawsuit, the plaintiff will suffer losses: the interest shall be calculated from the due date to the actual repayment, and the standard may be calculated based on the LPR. The accounts must be traced back and settled completely.

1. Problem background and typical scenarios

The payment was delayed for two years, and the lawsuit only mentioned the principal amount. When the judge asked at the hearing, "Do you claim interest?" the company suddenly remembered this. Although it was still possible to add the claim, the company failed to provide evidence of the standard and starting point of the interest, and the final amount was far lower than expected. The interest on the payment is a "silent loss" that won't be automatically credited. Companies with unclear claim paths and starting rules are effectively giving interest-free loans to defaulting parties every year.

II. Key points of contention

First, the application of agreed interest and statutory interest. Second, the determination of the "due date". Third, the choice of interest calculation standards. Fourth, the relationship between interest claims and the statute of limitations.

III. Professional analysis by Henglue Law Firm

First, priority of agreements: Where the contract explicitly stipulates that "the default penalty shall be 5‰ of the overdue amount per day" or "interest shall be calculated at an annual rate of 18%", the party may request a reduction of the excessive default penalty (exceeding the reference line of 30% of the actual loss) or claim compensation for the actual loss if the penalty is too low. Where there is no stipulation on overdue interest, it does not mean there is no interest at all - according to Article 580 of the Civil Code and the judicial interpretation of sales contracts, if the seller claims compensation for the loss of overdue payment on the grounds of the buyer's breach of contract, the court may calculate it based on the LPR plus 30% to 50%. Second, determination of the "due date": - If there is a payment deadline in the contract, the day following the expiration of the deadline shall be the starting date; - If the contract stipulates that "payment shall be made after the acceptance of the goods", the date of acceptance shall be the due date; - If there is no stipulation on payment time, Article 511 of the Civil Code shall apply - the buyer shall pay upon receipt of the subject matter or collection of the documents, i.e., the date of delivery; - For installment payments or partial deliveries, the payment shall be correspondingly calculated; - If the statement of account confirms the payable amount, the date of confirmation of the statement of account shall be a more definitive starting point - the significance of the statement of account is not only to confirm the amount, but also to fix the starting time. Third, selection of calculation standards: - If there is no stipulation on default penalties, claim based on "LPR plus 30%–50%", and directly state the added percentage and reasons (malicious delay of payment, long period of fund occupation) when claiming; - If there are default penalty clauses, follow the stipulated standards, noting that default penalties and interest cannot be claimed concurrently - specify one or the other in the lawsuit; - The claim period shall start from the due date and continue until the actual repayment; unpaid interest after judgment shall continue to be calculated. Fourth, linkage between statute of limitations and interest: - The statute of limitations for the principal of the loan is three years, and interest shall follow the principal - if the lawsuit does not claim interest, it shall be deemed as waiving this part of the claim (the case is extinguished), and claiming it separately will face the risk of "non bis in idem". Therefore, it is necessary to include both interest and default penalties in the claim when suing; - The statement of account and reminder letter simultaneously interrupt the statute of limitations and fix the default status, serving dual purposes. Fifth, practical suggestions: - Clearly stipulate the two elements of "payment deadline + overdue interest or default penalty standard" in the contract's payment terms; - Include the "due date" in the statement of account when conducting account reconciliation; - Specify in the reminder letter that "interest shall be calculated at the agreed standard from the due date"; - Conduct quarterly reconciliation of accounts receivable ledgers, and roll over the interest and principal simultaneously.

IV. Practical Suggestions and Legal Basis

The first step is to check whether the contract includes payment deadlines and interest clauses. The second step is to secure evidence of the due date (delivery, acceptance, account reconciliation). The third step is to claim both the principal and interest in the lawsuit. The fourth step is to specify the standard interest rate according to the contract or the LPR plus a surcharge. The main legal basis: Articles 501, 501, and 580 of the Civil Code of the People's Republic of China, Article 18 of the Interpretation of the Supreme People's Court on Legal Issues in the Trial of Disputes over Sales Contracts; the specific application shall be subject to the currently effective provisions.

5. Henglu Law Firm's Reminder

Three key points regarding loan interest: 1. If there is an agreed standard, interest starts from the day following the agreed date. If there is no such agreement, interest is calculated based on the LPR (Loan Prime Rate) plus a markup of 30% to 50%. 2. The due date depends on three key points: delivery, acceptance, and reconciliation. The reconciliation statement serves as the most conclusive timestamp. 3. If interest is not included in the lawsuit, it constitutes a voluntary waiver of rights. The principal, interest, and penalty charges should be consolidated into a single claim. For matters involving the recovery of loans and interest, legal action can be initiated through the following channels:Creditor's rights and debts, and enforcementThe service provides a comprehensive solution, and for disputes involving sales contracts, it can be combined with other services.Business and contract disputes in enterprisesFor reference, you can check the modules related to enterprise accounts receivable managementIntellectual property protection and corporate lawFor inquiries about special cleaning services, please refer to the relevant columnSpecial servicesTeam.

VI. Frequently Asked Questions

Q1: Can't I claim interest if it's not specified in the contract?

It can be claimed. Where there is no agreement on overdue interest, the party may claim damages for overdue payment based on the LPR, plus an additional 30% to 50% of the LPR, calculated from the date on which the payment is due.

Q2: Until when can the interest be calculated?

The interest shall be calculated until the date of actual repayment; if the debtor fails to perform the obligation after the expiration of the performance period determined by the judgment, the interest on the unpaid part of the debt shall be calculated in accordance with the rules of the enforcement procedure and doubled.

Q3: If the agreed penalty for breach of contract is too high, will it be adjusted?

The other party may request a reduction. The judicial reference shall be based on the actual losses and the increase shall not exceed 30%. When making the claim, please prepare evidence of the actual losses.

Q4: What is the legal value of a bank statement?

Confirming the amount of the debt and the due date is the anchor point for calculating interest, and it also constitutes a confirmation of the interruption of the statute of limitations. A single document serves three functions.

Q5: If I only sue for the principal amount when filing a lawsuit, can I still claim the interest later on?

There are risks involved. If the claim does not include interest, it will be considered as a waiver of processing that part of the request. Additionally, there might be obstacles to filing a new lawsuit if the same matter has already been dealt with. Therefore, it is essential to include interest in the claim before filing a lawsuit.

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 currently facing similar problems, it is recommended that you consult a professional lawyer as soon as possible with the necessary evidence 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 publicly available 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. In the event of a dispute, please consult a practicing lawyer in a timely manner.