Template · Clean · Opening soon

Find duplicate invoices before you pay them twice

Point it at your supplier bills or payments. It lists every pair from the same supplier with the same amount and close dates or the same bill number, on every refresh.

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You bring

Bills77 rows

SupplierDateAmount

Mammoth does the work

You get

One table3 rows

Pairs of bills that look paid twice: same supplier, same amount, close dates or the same number.

Same bill numberSame amount, same daySame amount, close dates

Not a spreadsheet to fill inIt is a ready-made workflow in Mammoth. You bring the files, and it does the work.
Your files, as they areUpload a file or connect a source. Your column names do not have to match.
Runs again by itselfWhen new data arrives, every step runs again and the result updates.

What you get back

The real result of this template, run on sample data.

Duplicate invoice check: the resultSample data3 rows

1 same amount, close dates1 same amount, same day1 same bill number

Supplier	Bill number	Date	Amount	Possible duplicate	Its date	Its amount	Days apart	Status
Brightline Telecom	B-3303	2026-10-21	1,569.11	B-3303	2026-10-12	1,569.11	9	Same bill number
Northern Couriers	B-3398	2026-08-08	1,268.83	B-3340	2026-08-08	1,268.43	0	Same amount, same day
Clean Team	B-3318	2026-09-13	449.19	B-3399	2026-09-16	449.19	3	Same amount, close dates

3 rows in the result · made from 77 input rows. Sample data: illustrative figures, not business results.

How do you find duplicate invoices?

Compare bills from the same supplier: the same amount within a few days of each other, or the same invoice number entered twice, are the usual signs. Supplier names are compared cleaned, so ACME LTD and Acme Limited count as one supplier.

How it works

How to use the duplicate invoice check template

1Bring your dataConnect a source, or upload a file.
2Check the columnsMammoth matches each column the template needs and asks only when it is unsure.
3Choose where it goesA table, a sheet, or a dashboard. It rebuilds on every refresh.

See the exact columns and steps ›

What it needs

Supplier bills or payments: supplier, date, amount (and bill number)

Bills

Supplier
Date
Amount
Bill number(optional)

The steps it runs

1Match columns
2Pairs that look paid twice

Every step is an ordinary Mammoth step you can open and change.

Duplicate invoice check: questions

Will it flag a monthly bill for the same amount?

Only when two land within the days you choose (14 by default). A subscription billed monthly falls outside that and is left alone.

Does it update by itself?

Yes. The template becomes an ordinary workflow in Mammoth. When your data refreshes, from a connector, a scheduled pull or a new file, every step runs again and the result table updates.

Can I change the steps?

Every step is an ordinary Mammoth step you can open and edit. Mammoth remembers which steps came from the template, so an update never overwrites your changes.

Do my column names have to match?

No. You point the template at your columns once. Mammoth suggests a match for each one and asks only when it is unsure.