# Sell a Service

URL: /products/service/sell · Id: `page:products/service/sell`

> Choose how buyers pay for the work, what the price counts and when it is collected, and what a buyer's agent reads before it orders.

A [Service](/business/nouns/service) sells through [Offers](/business/nouns/offer) whose shape matches how the buyer already pays for this kind of work. The price counts what the Service's checks can prove, and nothing earns before the buyer accepts.

## How buyers pay
| Shape | The buyer pays | Each purchase is |
| --- | --- | --- |
| Package | A fixed price for a fixed scope | One [Order](/business/nouns/order) |
| Retainer | Monthly, for a set amount of work | A [Subscription](/business/nouns/subscription), with an Order per delivery |
| Per delivery | Each accepted delivery | An Order per delivery, billed on acceptance |
| Scoped quote | A price set for this job | A [Quote](/business/nouns/quote), accepted into an Order |
| Booked session | A slot on the calendar | An Order held to a time |

[How customers buy a service](/products/service/ordering) covers each shape with its bound.

## What the price counts
An Offer's `basis` names what its price counts: `access`, `effort`, `usage`, `output` or `outcome`. The Service's assurance caps it, because a price on an outcome needs a check that measures the outcome.

| Assurance of the weakest check | Highest `basis` |
| --- | --- |
| `declared` | `effort` |
| `estimated`, `sampled` | `usage` |
| `graded`, `attested` | `output` |
| `measured`, `confirmed` | `outcome` |

Catalogmend's checks are `graded`, so it prices per listing fixed, an `output`. It cannot price per sale the fixed listings bring in, because no check measures that before the fee is earned.

## When it is collected
`payment` separates collecting from earning: `onEarn`, `deposit`, `prepaid` or `milestones`. A deposit Offer collects its `depositShare` at the order. Revenue still posts only on the [Event](/business/nouns/event) the contract `earns` names.

## What a buyer's agent reads
A buyer's agent reads the Offer and its contract as data: done, the window, revisions and the remedy. It asks in the `try` [Mode](/business/nouns/mode) whether the Service covers its input, then orders inside its [Mandate](/business/nouns/mandate). An Offer listed for agent buyers needs `graded` checks or an [Evaluator](/business/nouns/evaluator) that accepts, so a buyer's agent never pays for work nobody checked.

[Selling to agents](/products/selling/selling-to-agents) shows a buyer's agent subscribing end to end.