Find duplicate and suspicious payments in an accounts payable export

Review the accounts payable data below for possible duplicate payments and other entries that need a second look, for {{reviewer}}, so they can check each one against the source documents before {{deadline}}.

Payments or invoices export:
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{{ap_export}}
"""

What each column means: {{column_notes}}

Supplier master list, if available (names, IDs, bank details, recent changes):
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{{vendor_master}}
"""

Our approval limits and payment rules: {{payment_rules}}

Look for:
1. Likely duplicates: the same supplier and amount within {{day_window}} days; the same invoice number paid more than once, including near matches such as a missing prefix, an added hyphen or two digits swapped; the same amount and date under two supplier records that look like one business.
2. Supplier issues: near-identical supplier names, the same bank details under different names, and payments to a supplier not on the master list.
3. Control flags: payments just under an approval limit, round-number payments with no invoice number, invoices dated after their payment, and payment dates on days our rules say payments do not run.

Return a table with the columns Flag, Rows (the row numbers or IDs involved), Supplier, Amount, Date, Reason flagged, What to check (the document or person that settles it), Likelihood (high, medium or low). Sort by likelihood, then by amount. After the table, give the number of flags and the total amount in high-likelihood flags, showing the sum.

For example, one row might read: "3 | rows 118 and 241 | [supplier as written] | 4,950.00 | both on the 12th | same amount, invoice number differs only by a hyphen | both invoice PDFs | high". This example shows the form only.

Use only the rows in the export, and quote identifiers exactly as they appear so the reviewer can find them. A flag is a reason to check, not a finding: do not call anything fraud or an error, and do not name an employee as responsible, because most flags turn out to have an ordinary explanation. Recurring payments that match by design, such as rent or subscriptions, are not duplicates; list them once under "Matched but likely recurring" so the reviewer can confirm. Keep the text outside the table under 200 words. A good review gives the reviewer a short list they can clear in one sitting, with the strongest flags first.

If a column needed for a check, such as invoice number or bank details, is missing, say which checks you could not run instead of skipping them silently.