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Glossary
Metered billing
Metered billing is the billing operation that closes a cycle by reading an accumulated usage total, converting it into priced invoice lines, and issuing the invoice after consumption happens. It runs in arrears, applies contract terms such as minimums and commitments at the close, and produces the amount a customer actually owes.
Key Takeaways
Metered billing is an operation on a schedule, not a pricing model. The model promises pay-per-use; metered billing is the cycle that dates and prices it.
The close is the defining moment. The quantity moves until the period ends, which is why a metered charge can't bill in advance.
A meter reading isn't always the number on the last day. Amazon S3 bills storage on the average amount stored across the month, in binary gigabytes.
A minimum splits the invoice in two: rated usage of $2,000 against a $2,500 floor yields a $500 shortfall line and a $2,500 total.
What happens when a billing cycle closes and a meter reading becomes an invoice line?
At the close, the billing system freezes the accumulated quantity, prices it, and writes it onto the invoice as a dated line. Everything upstream belongs to usage metering, which captures and counts the events; metered billing starts where the counting stops. The Flexprice guide to metered billing walks the full setup.
The close runs in a fixed order:
The billing period boundary hits and no new usage lands in that period.
The system resolves the reading: a sum for counters, an average or peak for level meters.
Rating turns the quantity into money using the tiers on the contract.
Contract adjustments apply in order: minimums, commitment drawdowns, credits, discounts.
The result lands on a draft invoice so corrections happen before the customer sees it.
Step two is the one I see teams get wrong. S3 bills on the monthly average stored, so a customer who deletes everything on the 30th still owes for the 29 days it sat there.
If metered billing and usage-based pricing aren't the same thing, where do they split?
They split on what each describes: usage-based pricing is the commercial promise, metered billing is the machinery that keeps it. Plenty of companies sell it and still close the month in a spreadsheet, which is the promise without the operation.
The practical differences:
Pricing is a decision made once per contract. Metered billing runs every period and has to be right every time.
Consumption-based pricing says nothing about timing. Metered billing forces billing in arrears, since no quantity exists to charge before the boundary hits.
One sentence describes usage-based pricing. Metered billing needs a period boundary, a reading rule, a rating step, and a correction window before it bills.
What happens when metered usage lands under a minimum or commitment?
The invoice charges the floor rather than the rated usage, and the gap shows up as its own line. Here's the same reading against a $2,500 monthly minimum, with API calls rated at $0.002 and billed in arrears:
Invoice line | Quantity | Rate | Amount |
API calls, metered, 1 to 31 August | 1,000,000 | $0.002 | $2,000.00 |
Minimum commitment shortfall | 1 | $500.00 | $500.00 |
Invoice total | $2,500.00 |
The shape of the floor decides how often that second line appears:
A monthly minimum resets every period and unused room disappears at the close.
An annual commitment lets a heavy month absorb a light one, with one true-up at term end.
A prepaid commitment reverses the order: the customer pays up front and each close draws the balance down.
Related terms
The close is one moment in a longer chain, and these entries own the steps around it.
The measurement layer that produces the reading: Usage Metering.
The step that turns a frozen quantity into money: Rating (Billing).
Why a metered charge can only bill after the fact: Billing in Arrears.
What defines the window a reading covers: Billing Period.
The correction window between the close and the sent invoice: Draft Invoice.
The commercial model this operation implements: Consumption-Based Pricing.
FAQ
Is metered billing prepaid or postpaid?
Metered billing is postpaid by default, because the quantity isn't knowable until the window ends. Prepaid setups still meter usage, but the close draws down a purchased balance instead.
Can a subscription fee and metered usage appear on the same invoice?
Yes, and most usage-based contracts do. The platform fee bills in advance for the period ahead while metered lines bill in arrears for the period that closed, so one invoice carries two date ranges.
What is a true-up in metered billing?
A true-up is the period-end adjustment reconciling what a customer consumed against what they committed to. It lands as its own line, charging the unmet commitment or crediting back an overcharge.
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