The billing words that are not interchangeable

A handful of words do most of the damage on a price page. They look like synonyms in marketing copy and behave differently on an invoice, which is why each one gets a page here instead of a parenthesis. As of 2026-09-12.

Fig. 1 Comparing a credit price against a per-second price is the single most common mistake a pricing grid invites.

A credit is an internal currency whose exchange rate the vendor sets and can change. A per-second rate is a price on finished output. An allowance is a cap that resets, and what happens at the cap — a stop, a queue, a higher rate — is a separate question that pricing pages rarely answer in the same place.

Mixing them produces the two mistakes this ledger sees most often: comparing a credit price against a per-second price as if they were the same unit, and treating an allowance as a quantity of video rather than a quantity of credits.

Each definition here is written to be quotable in one sentence and linked from anywhere a page uses the word, so the argument only has to be made once.

1The terms

Credit billing — Plan credits and purchased credits expire on different schedules, and vendors differ on whether a failed generation is refunded.
Resolution tiers — Across the three tiers recorded here, the lower resolution rate runs from 50% to 100% of the higher one.
Prompt extension — Several models rewrite the prompt before generating, and it is on by default.
Per-video billing — A figure attached to a whole generation rather than to a second of it.
Run-time billing — A meter that counts hardware occupancy rather than delivered output.
Conditional rate — A figure reachable only under a condition the page states: a queue, a clock, a commitment, or a promotion with no end date.
Concurrency — The number of generations a channel will run at the same time.
Credit allowance — A number of credits granted each period.
Credit validity — The window in which a credit can be used.
Output unit — What a published figure is attached to.
Clip ceiling — The maximum length of a single generation.
Wholesale floor — Agreement to the cent across unrelated shops usually means an input cost passed through with thin margins, and it moves the decision elsewhere.
An unrated cell — An unrated criterion means nothing usable is published.
Credit hold — Some vendors take credits when a task is submitted and settle when it ends.
Draft pass — A draft pass renders every shot at a low rate to find mistakes, then pays the high rate once per kept shot.

Definitions are the ledger's own, written to be checkable against the vendor pages they describe rather than against industry habit.

Elsewhere on the ledger: Channels, Ratings, Unpriced, Price shapes, What each channel publishes, One model, several sellers, Single ratings, Questions, Learn, Data. How a figure earns a line is set out on the method page.

2The production behind the price

Price aside, what goes into the seconds behind “Terms” is described in SceneMixer's guides:

A SceneMixer segment comes out with its sound already in it: each line spoken in that character’s voice, the speaker’s lips moving with the words, and the ambience of the place — rain, traffic, a clock.
SceneMixer, Dialogue and Sound in One Generation (read 2026-10-13)

The second trim replaces the first trimmed version; the generated clip stays in Version History.
SceneMixer, Trim a Clip: Cut the Start or the End Without Regenerating — “Can I trim the same clip twice?” (read 2026-10-13)