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Lease amortization schedule

Build a lease amortization schedule from your lease contracts export in Excel. You get monthly liability, interest, and payment for each lease, with fixed payments kept fixed for CPI step-ups.

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Someone typed

“build the lease amortization schedule for each lease with the liability, interest and payment each month”

The agent read it as

Build the lease amortization schedule for each lease with the liability, interest and payment each month from Lease contracts, keeping the listed payment fixed for leases with CPI step-ups.

What the agent built

1 step, each one an ordinary Mammoth step you can open and change.

File

Lease contracts

CSV export · 12 rows

Step

Build monthly lease schedule

Step 1

Result

Lease Amortization Schedule

456 rows

Schedule

Runs when you say

Proposed

File
Lease contracts
CSV export · 12 rows
Step
Build monthly lease schedule
Step 1
Result
Lease Amortization Schedule
456 rows
Schedule
Runs when you say
Proposed

Checked on the sample files: every step ran, 456 rows came out.

Download Lease contracts sample (12 rows)Excel: Lease workbook > Lease contracts sheet > Save As CSV

What you get back

The result of that run, the rows to look at first.

Lease Amortization ScheduleSample data456 rows

Lease ID	Month	Liability	Interest	Payment
LS-1001	2026-01-01	393,272.84	2,436.82	12,500
LS-1001	2026-02-01	383,148.86	2,376.02	12,500
LS-1001	2026-03-01	372,963.72	2,314.86	12,500
LS-1001	2026-04-01	362,717.04	2,253.32	12,500
LS-1001	2026-05-01	352,408.46	2,191.42	12,500
LS-1001	2026-06-01	342,037.59	2,129.13	12,500
LS-1001	2026-07-01	331,604.07	2,066.48	12,500
LS-1001	2026-08-01	321,107.51	2,003.44	12,500
LS-1001	2026-09-01	310,547.54	1,940.02	12,500
LS-1001	2026-10-01	299,923.76	1,876.22	12,500
LS-1001	2026-11-01	289,235.80	1,812.04	12,500
LS-1001	2026-12-01	278,483.27	1,747.47	12,500

456 rows in the result · 12 shown, problems first. Sample data: illustrative figures, not business results.

How do you build the lease amortization schedule for each lease?

Export your lease contracts from Excel and upload the file. Mammoth reads each lease, then builds a monthly schedule with liability, interest, and payment for each month. For leases with CPI step-ups, the listed payment stays fixed in the schedule.

How it works

How to use the Lease Amortization Schedule workflow

1Get early accessWe invite people in small batches, job by job. You'll land on this workflow, already built and checked on the sample files.
2Swap in your exportsUpload your own files as they come out of your tools. The agent checks the workflow on your rows.
3Change it in words, then turn it onSay what to change and see the new result before anything saves. Then choose when it runs.

Lease Amortization Schedule: questions

What export should you use?

Use the Excel export that contains your lease contracts. The file should include the lease details needed to calculate the monthly schedule, including the payment terms.

What happens if a row does not match the rules?

Rows that do not match stay out of the result for that step. You can review them, then adjust the source data or the rule so they fit the same structure as the other leases.

How do you change the rules?

Edit the step in words to change what you want calculated or how rows are grouped. You can also add or change conditions, such as which lease terms to keep fixed, then run the workflow again.