[Direct answer]The interest shall be calculated from the date of payment of the project price. Where the parties have no agreement on the time of payment or the agreement is unclear, it shall be determined according to the following circumstances: if the construction project has been actually delivered, it shall be the date of delivery; if the construction project has not been delivered, it shall be the date of submitting the completion settlement documents; if the construction project has not been delivered and the project price has not been settled, it shall be the date on which the party files a lawsuit. The interest rate is usually calculated according to the interest rate for similar loans issued by the People's Bank of China during the same period or the loan market quotation rate. Where there is an agreement, it shall be in accordance with the agreement (if the agreement is obviously too high or too low, the party may request an adjustment). Therefore, the key to claiming interest is to determine the time of payment and calculate and calculate it accordingly.

1. Problem background and typical scenarios

The project payments have been delayed for many years. When the contractors sue, they often only claim the principal and ignore the interest; some people don't know when the interest starts to accrue, resulting in a significant difference between the claimed amount and the actual amount they should receive. The starting point of interest not only affects the amount, but also influences the determination of the statute of limitations. It is a common focus of dispute in settlement negotiations.

II. Key points of contention

First, the determination of the date for settling the project payment and the application of the three scenarios; second, the handling of the situation where the contract stipulates the payment time; third, the selection and adjustment of the interest calculation standard; fourth, the starting point for installment payments and partial settlements; fifth, whether interest and penalties can be claimed simultaneously.

III. Professional analysis by Henglue Lawyers

The first step is to determine the "due date for payment". If there is a clear agreement in the contract, the due date shall be determined according to the agreed time; if there is no agreement or the agreement is unclear, the due date shall be determined according to three circumstances: whether the project has been delivered, whether the settlement documents have been submitted, and whether the case has entered the litigation stage. In practice, the contractor should keep the delivery and acceptance records and the submission certificates of the completion settlement documents to fix the due date for payment.

The second layer is that the interest rate standard should be selected in accordance with the regulations. It is usually calculated by referring to the interest rate of similar loans or the loan market quotation rate during the same period; if the interest rate is stipulated in the contract, it shall be calculated according to the contract, but if the stipulated standard is obviously deviated from the market level, one party may request an adjustment. The interest calculation period is from the date of payment to the actual repayment date. When suing, it can be temporarily calculated to the date of suing and claim subsequent interest.

The third layer involves calculating the interest separately for each installment and partial settlement. If the project payment is made in installments, the interest for each installment shall be calculated from the date of payment due for that installment; for partial settlements where the confirmed amount has been determined, interest can be claimed separately on the confirmed portion to avoid delaying the claim for interest on all payments due to disputes over the overall settlement. Based on the practical experience of handling project payment cases by Henglue Lawyers, claiming the confirmed creditor's rights and corresponding interest separately is often more efficient than handling the overall dispute together: on the one hand, it can shorten the trial and evidence-gathering period; on the other hand, it can also initiate preservation and enforcement measures as soon as possible, reducing the loss of funds being occupied for a long time.

Fourthly, the connection between interest and the penalty for breach of contract needs to be clarified. If the contract stipulates both the penalty for late payment and the claim for interest, the claimant generally cannot receive compensation twice for the same period. The claimant should either choose one or claim in a way that is favorable to himself/herself; if the stipulation is unclear, it is safer to calculate the interest according to the legal interest rate standard. When making the claim, the claimant should specify the calculation base, the start and end time, and the interest rate standard, and form a clear calculation table.

IV. Practical suggestions and legal basis

First, preserve the delivery and acceptance records and the submission certificates of the completion settlement documents. Second, specify the due date and determine it according to the three scenarios. Third, prepare an interest calculation table, indicating the base amount, period, and interest rate. Fourth, when the contract stipulates both the penalty for breach of contract and the claim for interest, attention should be paid to avoid double compensation. Fifth, promptly file a lawsuit and claim interest until the actual repayment date. Main legal basis: The Interpretation of the Supreme People's Court on the Application of Law in the Trials of Construction Contract Disputes (I) regarding the provisions on interest on unpaid project payments, and the relevant provisions of the Contract Chapter of the Civil Code of the People's Republic of China; the specific application shall be subject to the currently effective provisions.

5. Henglu Law Firm's Reminder

There are three key points regarding interest on project payments: one of the three options—the date of payment, the date of settlement submission, or the date of litigation—is selected based on the date of payment; the interest rate is either referenced to the prevailing loan interest rate or the loan market quotation rate, or determined by contractual agreement; and interest and penalties should not be claimed concurrently. Clear calculations must be provided in the calculation table. For cases involving real estate transactions and construction projects, litigation may be initiated through the following channels:Property transactions and construction projectsThe service provides a comprehensive solution, which can be integrated with the execution of the project payment.Creditor's rights and debts, and enforcement casesFor reference, you can check the clauses related to contract performanceBusiness and contract disputes in enterprisesFor the column, if you need a comprehensive solution, please feel free to consult usSpecial servicesTeam.

VI. Frequently Asked Questions

Q1: When does the interest on the project payment start to be calculated?

The payment shall be made from the date of settlement of the project price. Where there is no agreement on the payment time or the agreement is unclear, the date of delivery of the project shall be the basis for determining the payment time; where the project has not been delivered, the date of submission of the completion settlement documents shall be the basis for determining the payment time; where the project has not been delivered and the settlement has not been made, the date of filing a lawsuit shall be the basis for determining the payment time. The key is to fix the corresponding evidence.

Q2: What evidence do I need to prepare to support my claim for interest?

It includes construction contracts and settlement documents, delivery and acceptance records, submission and delivery certificates of completion settlement documents, payment records and confirmation materials of arrears, as well as interest calculation tables. The materials should be able to determine the due payment time and the amount of arrears, so as to facilitate the court's calculation of interest.

Q3: How much do lawyers charge for engineering payment disputes?

The fees are subject to market regulation and are usually negotiated based on the subject matter and the workload. Fees for cost appraisal, preservation, and enforcement are charged separately. The fees will increase correspondingly if the subject matter is large or the disputes are complex. It is recommended to clarify the scope of services and the charging method before signing the contract, and to require a separate breakdown of the fees paid on behalf of the client.

Q4: How long does it take to handle cases like this?

The first-instance trial generally follows a simplified procedure, which typically lasts three months, and an ordinary procedure, which typically lasts six months. The second-instance trial generally lasts three months. The duration of the trial involving cost appraisal or quality appraisal will be extended. It is recommended to file a lawsuit and apply for property preservation as soon as possible to prevent the other party from transferring assets and affecting the execution of the judgment.

Q5: If the contract stipulates a high penalty for breach of contract, can I still demand interest?

Generally, it is not allowed to receive compensation repeatedly for the same period. One should either assert one claim or handle the matter in a way that is favorable to oneself. If the agreed penalty is obviously too high, the other party may request an adjustment. In this case, it is usually more secure to calculate the loss of principal occupation according to the statutory interest rate. It is recommended to seek advice from a lawyer before making a choice.

The above content is based on the judicial practice in the Beijing area. The facts of individual cases and the jurisdiction of the court may affect the conclusions. Welcome to consult Henglue Lawyers about specific situations.

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. →Legal services for real estate transactions·Beijing Henglu Law Firm

Disclaimer: This article is compiled based on the current effective laws and regulations and public 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.