Insights
How to Set AI Approval Thresholds That Work
A $200 monthly AI experiment rarely needs the same scrutiny as an agent that can create a $40,000 annual run rate in a week. The challenge is to set AI approval thresholds that prevent surprise costs without turning every useful use case into a procurement exercise. Good thresholds make spending decisions visible, assign an owner, and give teams a fast path to proceed when the economics make sense.
For finance, this is a control problem. For platform and AI teams, it is an operating model problem. The shared goal is not to restrict access to AI. It is to make sure the organization knows who committed spend, what business activity created it, and when a growing experiment should become a managed service.
Why AI approval thresholds need a different design
Traditional software approval policies often focus on contracts: a new vendor, an annual commitment, or a purchase order. AI spend has those events too, but its most expensive moments often happen after the contract is signed. Usage-based APIs, cloud model endpoints, agent loops, and gateway traffic can increase materially without a new invoice or a new vendor review.
That means a policy based only on total vendor spend will miss the operational signal. A central invoice may show $80,000 in monthly AI charges, while the underlying usage comes from dozens of agents, business units, projects, and cost centers. A threshold that says "approve all AI spend over $10,000" gives finance little ability to see which decision actually caused the spend.
The better approach is to define thresholds at multiple levels: the individual experiment or project, the team or cost center, the production agent, and the company-wide vendor commitment. Each level answers a different question. Is this a reasonable experiment? Is a team staying within its budget? Is a production workload behaving as expected? Is the company taking on a commercial obligation it can support?
Set AI approval thresholds around decision rights
Before selecting dollar amounts, assign who can approve each kind of decision. Thresholds without decision rights create escalation theater: everyone is copied, but nobody knows who owns the call.
A practical model usually has three layers. A team lead can approve a small, time-boxed experiment from an existing budget. A business owner and finance partner approve a production use case that will create recurring spend. Procurement, finance leadership, and the relevant technology owner approve new vendor commitments, material usage commitments, or exceptions to standard controls.
The dollar figure matters, but it should not be the only trigger. An AI workload should also require review when it crosses a change threshold. Moving from internal testing to customer-facing use, connecting to a sensitive data source, enabling autonomous actions, or shifting from a fixed pilot budget to open-ended consumption are all meaningful changes. They can alter cost behavior even if this month's bill remains small.
Start with a pilot ceiling and an expiration date
For early-stage work, use a small ceiling that teams can access quickly. For example, a department head might approve up to $2,500 for a 30-day experiment, provided the project has a named cost center, owner, purpose, and planned success measure.
The expiration date is as important as the ceiling. Without it, pilots become permanent workloads with temporary governance. At the end of the pilot, the owner should either shut it down, renew it with a new ceiling, or submit a production case with a forecast and an accountable business sponsor.
This is not bureaucracy for its own sake. A $2,500 pilot can reveal whether an agent saves enough analyst time, reduces support handling time, or improves a revenue process to justify ongoing spend. If nobody is expected to answer that question, finance has no reliable basis for forecasting the next quarter.
Use production thresholds based on run rate, not one invoice
A single monthly bill can be noisy. A better trigger is expected monthly run rate. If an agent spends $1,200 in its first 10 days, the relevant approval question is not whether the current invoice is under $2,000. It is whether the workload is on track for roughly $3,600 per month and whether that run rate is within the team's approved budget.
Many organizations use a tiered approach. The exact figures depend on company size and budget structure, but the logic is consistent:
- Low run rate: team-level approval, a named owner, and a monthly budget alert.
- Moderate run rate: business sponsor approval, finance review, and a documented forecast for the next quarter.
- High or enterprise-wide run rate: formal vendor, security, architecture, and finance review, with a documented allocation method and executive accountability.
- Material variance: escalation when actual usage exceeds forecast or approved budget by a defined percentage, such as 20 percent, even if the absolute amount remains below a standard approval limit.
Percentage variance matters because $5,000 above plan is very different for a $10,000 budget than for a $500,000 budget. Use both an absolute dollar threshold and a percentage threshold so material deviations are not hidden by a one-size-fits-all rule.
Tie each threshold to a measurable financial record
Approval controls work only when usage can be attributed. If all AI costs land in one shared technology account, finance can approve a budget but still lack the evidence to explain the actual charge. Every approved workload should therefore carry a minimum set of financial identifiers: cost center, project or product code, business owner, technical owner, vendor or platform, and budget period.
For shared platforms, define an allocation method before the charges become material. Token usage, model inference calls, compute time, active users, or transaction volume can be reasonable drivers. The right method depends on what causes cost and what managers can influence.
Consider an internal customer support agent that costs $18,000 in a month. If usage data shows that Support generated 70 percent of requests and Operations generated 30 percent, the allocation can be booked accordingly. The internal entry might debit Support AI Expense for $12,600 and Operations AI Expense for $5,400, while crediting a central Technology AI Clearing account for $18,000. The purpose is not to create accounting complexity. It is to put the cost where operating decisions are made.
When attribution is incomplete, do not invent precision. Book the known portion to the accountable cost center and place the residual in a clearly labeled shared AI cost pool. Then make closing the attribution gap an operating requirement for continued production approval.
Build escalation paths that do not slow productive teams
A threshold policy fails when the only response to a budget alert is "stop using AI." That may be appropriate for an abandoned experiment, but it is a poor default for a revenue-critical or customer-facing workflow. The escalation should give owners options.
When a workload approaches its ceiling, the first review should ask what changed. Did volume grow because adoption succeeded? Did the model mix change? Is an agent retrying failed requests? Did a new release remove usage limits? The remediation could be a higher approved budget, a usage cap, a model-routing change, a technical fix, or a decision to retire the workload.
Set response expectations in advance. A low-risk pilot may only need a weekly alert. A production agent that reaches 80 percent of its monthly budget might notify the business and technical owners immediately, require a forecast update within two business days, and pause nonessential expansion until the owner approves the revised run rate. Higher-risk thresholds may require finance sign-off before additional consumption is authorized.
This structure protects teams from arbitrary intervention. It also protects finance from being asked to approve an unexplained overage after the invoice arrives.
Treat approval evidence as part of the close process
Controllers need more than a screenshot of a dashboard. For material AI spend, retain the approval record, budget amount, forecast, owner, allocation method, and explanation for significant variance. The evidence should show the approval was made before or at the time of the spending decision, not reconstructed at month-end.
A monthly operating review can connect these records to the ledger. Compare actual vendor charges to metered usage, reconcile allocated costs to the central invoice, identify unassigned spend, and review exceptions. This is where finance and platform teams can resolve the same question from different angles: finance asks whether the expense is accurately recorded; technology asks whether the workload is behaving as intended.
The first version of a threshold policy does not need to be perfect. Start with the AI workloads that account for most spend or the greatest growth, establish owners and time-bound budgets, then refine limits as usage data improves. The useful outcome is a repeatable habit: when AI usage grows, accountability grows with it.
Not sure which of your AI costs are being booked? Run the free Agent Spend Assessment.
Onaro Meridian is FinOps for agentic AI: the system of record that attributes, controls and books what AI agents spend.

Brian Diamond
Brian Diamond is a fractional Chief AI Officer and founder of Onaro. He has spent 30 years running infrastructure operations and founded LANStatus, a Connecticut managed services provider and Microsoft partner, in 2001. He holds a Chief AI Officer certification and writes the CAIO Brief on AI leadership for finance and operations.