Split transactions below an approval threshold
Detects purchases broken into smaller charges or reports that each fall under an approval limit but together exceed it, such as charges of $1,284.60 and $1,317.46 days apart.
- Employee
- Lucas Fernández, IT Operations Manager, Kestrel Aerospace Components
- Merchant
- CDW Direct, two orders (#INV-5583120 and #INV-5583147)
- Amount
- $2,602.06
Lucas placed two CDW orders on September 16 and September 18 for $1,284.60 and $1,317.46, each under the $1,500 single transaction limit on his card. Together they total $2,602.06, above the $2,500 purchase threshold that requires director approval. The invoices are 27 numbers apart, ship to the same address, and list matching docking stations and monitors divided across both orders.
- Category
- Duplicates & fraud
- Default severity
- High
- Basis
- Company policy
- Rule ID
- split-transaction-threshold
Why this rule exists
Approval thresholds exist because larger purchases deserve a second look. A $2,500 limit on a card or a report means anything above it needs a budget owner's sign-off. Splitting a $2,602.06 purchase into two charges, or into two reports filed a few days apart, keeps each piece under the line, and the second look never happens.
Sometimes this is a workaround for a slow approval process rather than anything worse, but the control is bypassed either way. Split purchases also hide vendor concentration and distort spend analysis, because one order shows up as two smaller ones.
Auditors treat split transactions as a red flag for good reason. The ACFE Report to the Nations finds expense reimbursement schemes are 14% of asset misappropriation cases, with a $40,000 median loss and 14 months median duration before detection, and staying under review limits is how small schemes stay small. A manager who spends under 30 seconds per report, as over 80% of front-line managers do according to industry survey data, sees two reasonable charges, not one large purchase.
Detection logic
The steps the audit engine runs, in order, on every submitted line.
- 01
Load every approval threshold that applies to the employee: single transaction card limits, report approval tiers, purchasing thresholds by category, and any department-specific limits from your policy configuration.
- 02
Find clusters of charges by the same cardholder, or by cardholders in the same cost center, at the same normalized merchant within three days, where each charge sits within 25% below a threshold.
- 03
Sum each cluster and raise a finding when the total exceeds the relevant threshold, for example two or more charges that each sit under $2,500 but together exceed $2,500 within the window.
- 04
Look across reports as well as cards. Two reports filed by the same employee within three days with the same merchant, project code or vendor invoice number are tested as one purchase.
- 05
Read invoice and order numbers on receipts. Near-consecutive invoice numbers, a shared purchase order reference or a receipt marked 'partial payment' strengthens the finding and is shown on it.
- 06
Ignore clusters that match a configured recurring pattern, such as weekly catering orders or monthly software seats, unless the frequency or amount departs from that established pattern.
The drafted message
Clause-cited, specific and easy to resolve in one click. AP edits or approves it before it reaches the employee in Slack, Teams or email.
Phyto Nex AI, on behalf of Finance
Draft, awaiting AP approval
Hi Lucas, thanks for submitting the CDW orders. I noticed two orders on September 16 and 18 for docking stations and monitors totaling $2,602.06. Section 3.6 of the Purchasing Policy asks that purchases above $2,500 for the same need go through director approval as one request, even when they are placed in parts. If these were for separate projects or teams, could you add that context? You can also upload the itemized receipts if the orders differ from what I read, or mark a line as personal if anything was ordered by mistake. Thanks!
Tuning tips
- Set the proximity band per threshold. A 25% band suits card limits, while purchasing thresholds with large gaps between tiers often work better with a fixed dollar band, such as $400 below the limit.
- Extend the window to seven days for categories where orders are naturally staggered, such as software licences or event supplies, and shorten it to one day for meals and ground transport.
- Include cost center clustering for teams where several people buy on behalf of one manager, which catches splits across cardholders that a per-person check would miss entirely.
- Exclude pre-approved blanket purchase orders by linking the PO number, so planned partial deliveries against an approved total do not generate findings each time an invoice arrives.
- Review the first month of findings with procurement. Some splits reveal thresholds set too low for normal work, and raising a limit can be a better outcome than repeated findings.
Basis
Company policy. There is no statutory requirement behind this rule, so thresholds are entirely yours to set.
Related rules
Next: Entertainment coded as a deductible meal- Duplicates & fraudWeekend and holiday spendFlags card transactions and reimbursements dated on weekends or company holidays with no overlapping trip, event or on-call record, a common early signal of personal spend on business cards.
- Duplicates & fraudDuplicate expenses across cards and reportsFinds the same purchase claimed twice, whether on a corporate card and a personal reimbursement, across two corporate cards, or in separate reports filed weeks apart.
- Meals & alcoholAlcohol without a client attendeeDetects alcohol on itemized restaurant and bar receipts when the attendee list has no external guest, so internal team drinks are separated from client hospitality your policy actually reimburses.
- SubstantiationMissing receipt at or above $75Checks that every expense of $75 or more, and every lodging charge at any amount, carries documentary evidence showing amount, date, place and nature of the expense.
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