Interest Calculation Services
Complex interest calculations handled by experts
Need help with complex or large-scale interest calculations? Let our expert team handle it for you – save time, avoid costly errors, and get accurate results you can trust.
Types of interest calculations supported
- Calculation of interest on hundreds or thousands of invoices
- One or multiple invoices by client and on various dates
- Partial payments can be included
- Fixed or variable interest rates
- Calculation of pre and postjudgment interest on one amount or multiple amounts (often judgments) over time, including regular or irregular payments, at fixed or variable interest rates
- Calculation of balances owed on mortgages, loans, lines of credit, etc. These can become quite complex and include late, partial or unpaid payments, fees, etc.
- Calculation of interest on arrears such as alimony, rent, salaries, or overtime wages
- Cost of credit (Annual percentage rate (APR)) calculations
How an interest calculation mandate is carried out
Initial analysis of your needs with one of our experts by phone
- Data calculation settings are discussed (simple or compound interest, compounding frequency, day count, interest rate(s), time period, etc.)
- Service cost sent to you
- You send the data to the Margill expert, usually in a spreadsheet with due dates, amounts, and a record identifier (anonymous or not). A non-disclosure agreement may be signed by Margill, but we prefer receiving and returning anonymous data.
- Problem data is identified (usually invalid dates) and corrected by the client – data then returned to Margill
- Calculation results are sent back in Excel or CSV format. Individual detailed calculations can also be sent in PDF format.
- We can store your results for a specified time period to extract any additional data you require (special balances, interest for a specific time frame, etc.)
- Our software can also be temporarily “rented” for a few days or weeks so you can extract other information from the resulting calculated data
All calculations are supervised by Marc Gelinas, Attorney, MBA, who has been deeply involved in the field for the over 30 years. Marc is the author of the White Paper: The Lost Art of Interest Calculation , originally published in Real Estate Law & Industry Report.
Business cases:
Interest on invoices:
Calculate the legal interest (variable rates) for over 1,500 invoices owed by as many seperate companies. Anonymized data (with identifiers) was sent to Margill in a simple spreadsheet containing the dates and amounts. The results were sent the following day with summary results and detailed calculations.
Overtime pay:
The mandate was to calculate the interest due on overtime pay for thousands of workers. An Excel file containing the workers’ unique identifiers, the number of hours owed for each date, the hourly rate, and a final calculation date was provided. The interest due to each worker was sent the following day.
For more information on this service please call or email us.
When interest calculations become recurring or increase in volume, some organizations adopt dedicated tools. Margill Loan Manager centralizes payments, interest, arrears and receivables across an entire portfolio. For one-off calculations outside a mandate, the Margill Interest Calculator allows teams to validate standard interest calculations with the same level of rigor. Teams can also rely on integrated interest rate tables to apply legal rates, banking rates or reference indices used in financial calculations.
Frequently asked questions about interest calculation services
Yes. Calculations follow applicable day-count conventions, legal or contractual rates and the rules defined for each mandate. The logic used is consistent and reproducible, which facilitates validation in audit or legal contexts.
The mandate begins with an analysis of requirements and calculation parameters. Data is then submitted by the client, reviewed and used to produce the results. Calculations are delivered promptly, in either detailed or summary formats based on client needs.
Yes. Clients may submit anonymized data, and a confidentiality agreement can be signed if required. Information is handled securely throughout the entire mandate.
Calculation services are performed by experts for specific or one-time mandates. Software solutions such as the Margill Loan Manager or the Interest Calculator are used directly by teams for recurring or internal needs. Both rely on the same calculation rigor.
Services cover interest calculations on invoices, judgments, loans, mortgages, lines of credit and arrears. Mandates may include irregular payments, late payments, fees and different day-count conventions. Each file is handled according to the parameters defined at the outset.
Interest calculation services are useful when calculations become complex, high-volume or legally sensitive. This is often the case with partial payments, variable rates, long time periods or multiple beneficiaries. They provide reliable results without the need for repeated internal validation.
For more information on this service please call or email us. Contact us