Stranded costs hide in plain sight. Find them. Kill them.

What stranded costs actually look like.

Stranded costs in a TSA are charges that continue after the underlying service has stopped being consumed. The most common pattern is the workstream exit. The buyer cuts over the HR system on Day 90. The seller's payroll service stops being used. The HR allocation on the seller's invoice continues for another six months because no one read the invoice line by line and triggered the termination.

A second pattern is the software licence that sits underneath a service. The seller's master agreement with the licence vendor specifies a seat count. The carved-out entity is consuming a defined share of those seats. When the carved-out entity migrates to its own tenant, the seat count under the seller's agreement should drop. In practice it does not, and the seller bills the original allocation through to the TSA end date.

A third pattern is the headcount allocation. The seller's shared services team had three people supporting the carved-out entity at Day One. By month six the carved-out entity has stood up its own team and the seller's three people are no longer engaged. The allocation continues until the buyer asks why.

Each of these is a cost line that has lost its operational reason but kept its invoice line. The sweep is what finds them. The mechanics of the broader cost discipline sit in TSA cost reduction tactics.

The quarterly sweep methodology.

The sweep is a structured exercise that takes a finance analyst and a workstream lead about two days per quarter. It happens on a fixed calendar. End of Q1, end of Q2, end of Q3, and at TSA termination. The output is a written disposition for every line on the seller's most recent invoice.

Step one is reconciliation of the invoice to the active service catalog. Every line on the invoice has to map to a line on the catalog. Lines that do not map are flagged. Lines that map to catalog services that have been terminated or substantially reduced are flagged. Lines where the volume on the invoice exceeds the documented consumption are flagged.

Step two is operational verification. The workstream lead confirms whether the service is still being consumed. If consumption has stopped or has dropped materially, the line goes onto the elimination list. If consumption has shifted to a different volume baseline, the line goes onto the renegotiation list.

Step three is the formal letter to the seller. Each line on the elimination list gets a termination notice under the TSA. Each line on the renegotiation list gets a volume restatement letter. The seller has 30 days to acknowledge and apply the changes to the next billing cycle.

Seller-side stranded costs the buyer pays for.

The seller-side stranded costs are the lines on the seller's invoice that should have stopped. These are the easier category to address because the TSA gives the buyer formal rights. The catalog defines what is being charged. The termination clauses define how a service ends. The audit rights allow the buyer to verify consumption against billing.

The seller is not necessarily acting in bad faith. The seller's billing operation runs against the catalog and the catalog has not been updated. The seller's account team has not been told the workstream exited because no one wrote it down. The buyer's termination notice is the document that triggers the seller's internal update.

When the seller resists a termination, the buyer's first move is to ask for the documentation supporting continued billing. What is the seller still delivering. To whom. Under what consumption pattern. If the seller cannot produce evidence of continued consumption, the line is terminated. If the seller produces evidence the buyer disputes, the dispute resolution clause is invoked.

Most seller-side stranded cost claims close out within 60 days of the termination notice. The seller's commercial calculation is straightforward. Defending a $30K monthly billing line through a formal dispute costs more in legal and management attention than conceding it. Disciplined buyers know this and use the sweep accordingly.

Buyer-side stranded costs that drag on after exit.

The other half of the sweep looks at the buyer's own cost base. When Newco stands up its own systems, the buyer takes on a parallel set of contracts. New software licences. New cloud capacity. New professional services retainers. These were sized at Day One based on an estimate of Newco's needs. By month six the actuals are visible and the original sizing is usually wrong.

The buyer's own quarterly sweep reviews the new contracts against actual usage. Software seats provisioned but not assigned. Cloud capacity provisioned but not consumed. Retainers paid but not drawn against. Each represents a cost reduction opportunity that closes if the contract anniversary passes without action.

A second buyer-side category is the duplicated cost. The buyer is still paying the seller for a service through the TSA and is also paying its own vendor for the same service in parallel. This happens when cutover runs late or when the buyer stood up the replacement before the seller's service could be terminated. The duplication is sometimes operationally necessary. It is never necessary for more than 30 days. The sweep flags any duplication older than that.

The buyer-side cleanup typically recovers 1 to 3 percent of Newco's total operating cost in the first year and the same again in years two and three as the run rate stabilizes. The discipline is exactly the discipline applied during TSA service catalog rationalization, but turned inward.

What the sweep produces in writing.

The sweep produces three documents. The disposition log lists every line on the invoice with a status, an action owner, and a target close date. The termination notice file holds the formal letters sent to the seller. The recovery tracker records the credits, the volume restatements, and the contract terminations as they land.

The disposition log is the operating document. It is reviewed weekly by the program director and quarterly by the governance committee. Lines that remain open across two sweeps are escalated. Lines that close are recorded in the recovery tracker. The cumulative recovery number is reported to the value creation team.

The termination notice file matters for two reasons. It is the audit trail that the buyer triggered the termination on a specific date, which determines when the billing should stop. It is also the record that disciplined buyers maintain to defend their position if the seller later disputes whether termination was properly noticed.

The recovery tracker is reported up. The PE operating partner sees the cumulative number quarter by quarter. A disciplined sweep on a $20M annual TSA recovers $1M to $2M against the original baseline. That is real money against the value creation plan.

The mistake of waiting until termination.

Most buyers run the sweep once, at the end of the TSA, when they are reconciling final invoices. This is the worst time to run it. By the end of the TSA, every stranded cost has been billed for as long as it was going to be billed. The recovery on a final sweep is limited to whatever the seller will credit retroactively, which is far less than what the seller would have stopped charging if notified at the time.

The contractual position also weakens over time. A termination notice issued in month three is uncontroversial. A backdated termination notice issued in month twelve, requesting a credit for nine months of stranded billing, generates a dispute. The seller's position is that consumption was not formally disputed at the time. The buyer's position is harder to evidence.

The quarterly cadence solves this. Every quarter the sweep runs. Every quarter the terminations are issued. The dispute window for each line stays open at the same time the operational evidence is fresh. Disciplined buyers report 80 to 90 percent of stranded cost claims close cleanly when the sweep is run quarterly. The same buyers running only the end of contract sweep recover 30 to 40 percent.

The quarterly sweep is not optional discipline. It is the operating routine that makes the TSA cost number real. The full discipline including invoice audit, true-up management, and pass-through verification is what disciplined buyer-side teams maintain as a standard practice. The sibling pattern of TSA shadow billing covers what happens when the seller's billing operation runs off a different rate card than the contract specifies.

More on TSA cost reduction.