Workflow · Reconcile · Opening soon

Duplicate payments check

Check vendor payments for duplicate payments in your QuickBooks export. Match each payment to its bill, then flag repeated amounts, invoice numbers, or missing bills.

Book a demo

Someone typed

“check the vendor list, bills list, and bill payment checks; match each payment to its bill and show amount, with Agrees for one normal bill match, duplicate payment, duplicate invoice payment, or no bill”

The agent read it as

check the vendor list, Bills list, and Bill payment checks; match each payment to its bill and show amount, with Agrees for one normal bill match, duplicate payment, duplicate invoice payment, or no bill

What the agent built

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

File

Bill payment checks

CSV export · 17 rows

File

Bills list

CSV export · 16 rows

Step

Group bill refs

Step 1

Step

Count payments

Step 2

Join

Bring bill details

17 of 17 paired

Step

Set status

Step 4

Result

Bill payment matches

17 rows · 2 flagged

Schedule

Runs when you say

Proposed

File
Bill payment checks
CSV export · 17 rows
File
Bills list
CSV export · 16 rows
Step
Count payments
Step 2
Step
Group bill refs
Step 1
Join
Bring bill details
17 of 17 paired
Step
Set status
Step 4
Result
Bill payment matches
17 rows · 2 flagged
Schedule
Runs when you say
Proposed

Checked on the sample files: every step ran, 17 rows came out, and the join paired 17 of 17 rows.

Download Bill payment checks sample (17 rows)QuickBooks: Expenses > Vendors > Bill payments > Run report > Bill payment details > Export
Download Bills list sample (16 rows)QuickBooks: Expenses > Vendors > Bills > Run report > Bill details > Export

What you get back

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

Bill payment matchesSample data17 rows

15 agrees2 duplicate payment

Payment date	Payment vendor	Check no	Payment ref	Payment amount	Bill ref	Bill amount	Status
2026-09-25	northline_packaging	ACH-9041	INV-2041	1,840	INV-2041	1,840	Duplicate payment
2026-10-15	northline_packaging	1189	INV-2041	1,840	INV-2041	1,840	Duplicate payment
2026-09-09	atlas_supply	1178	B-8801	1,240	B-8801	1,240	Agrees
2026-09-13	blue_harbor_media	ACH-9021	INV-2034	960	INV-2034	960	Agrees
2026-09-16	cedar_peak_it	1181	CP-4410	2,150	CP-4410	2,150	Agrees
2026-09-19	delta_freight	ACH-9034	DF-7712	680	DF-7712	680	Agrees
2026-09-23	evergreen_cleaning	1184	EC-5591	420	EC-5591	420	Agrees
2026-09-27	riverstone_print	1186	RP-1188	730	RP-1188	730	Agrees
2026-10-02	summit_catering	ACH-9052	SC-3320	510	SC-3320	510	Agrees
2026-10-04	atlas_supply	ACH-9055	B-8834	875	B-8834	875	Agrees
2026-10-07	blue_harbor_media	1188	INV-2049	960	INV-2049	960	Agrees
2026-10-11	cedar_peak_it	ACH-9063	CP-4462	1,280	CP-4462	1,280	Agrees

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

How do you check for duplicate payments from QuickBooks exports?

Export your vendor list, bills list, and bill payment checks from QuickBooks, then load them into the workflow. It groups bill references, counts payments, brings in bill details, and sets a status for each match. You can see normal bill matches, duplicate payments, duplicate invoice payments, and rows with no bill.

How it works

How to use the Bill payment matches 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.

Bill payment matches: questions

Which QuickBooks export should you use?

Export the vendor list, bills list, and bill payment checks. Those files give you the vendor, bill, and payment data the workflow needs to compare rows.

What happens to rows that do not match a bill?

They are kept as their own result and marked as no bill. You can review them separately so you can check whether the payment was entered differently or should be corrected.

How do you change the duplicate payment rules?

Edit the matching rules in words, then rerun the workflow. For example, you can change what counts as a duplicate by vendor, amount, invoice number, or date window.