# What is source to pay?

> Source to pay is procure to pay plus the work before it: finding suppliers, running bids and signing contracts. Definition with an example.

Updated 2026-11-06. Source: https://atta.sh/glossary/source-to-pay

Source to pay, or S2P, extends procure to pay backwards to cover sourcing: choosing categories to manage, finding suppliers, running tenders and negotiating contracts, then the buying and payment cycle that follows.

## Example

A school group decides to consolidate classroom supplies. It sends a tender to 8 suppliers, scores bids on price and delivery, and signs a one-year contract with two at 12% below list. After that, teachers raise requests that buy from those contracted suppliers, and invoices are matched to POs.

Everything up to the contract is the source half. Everything after is procure to pay.

## In Atta

Atta works on the pay half and on everyday sourcing. The agent searches the stores a workspace allows, applies brand and store preferences (a "never" is a filter in code), and compares prices and delivery dates for each request. A supplier can have a catalog with price, minimum and quoted lead time, and supplier scores summarise how it performs.

See [procure to pay](https://atta.sh/procure-to-pay).

## When it's worth it

Sourcing events pay off when a category is large and repeats, such as the school's classroom supplies. For a one-off $300 purchase, running a tender costs more than the saving. Most companies end up with S2P for a few categories and plain P2P for the rest. The school group above would likely leave one-off repairs and event purchases outside the contract and buy them case by case.

## Questions

### Do small companies need source to pay?

Usually they need the pay half first. Sourcing events matter once recurring spend with a category is large enough to negotiate.