---
title: "How Barton Associates reduced invoice disputes by 52% with Nace"
description: "A locum tenens staffing agency checks its invoices against the assignment's contract before they go out. In the first eight weeks: 52% fewer invoice disputes, invoices out 50% faster and days sales outstanding 14% lower."
canonical: "https://nace.ai/business/customers/barton-associates"
updated: 2026-10-08
---

# How Barton Associates reduced invoice disputes by 52% with Nace

> A locum tenens staffing agency checks its invoices against the assignment's contract before they go out. In the first eight weeks: 52% fewer invoice disputes, invoices out 50% faster and days sales outstanding 14% lower.

Customer story · Oct 8, 2026 · Nace.AI

- Customer: [Barton Associates](https://www.bartonassociates.com/)
- Industry: Healthcare staffing
- Region: United States

- Invoice disputes: 52% fewer invoice disputes and adjustments
- Time to invoice: 50% faster from the end of the work week to invoice submission
- Collections: 14% lower days sales outstanding

Barton Associates brought contract verification into its billing workflow with Nace, connecting contract terms, timesheets, expenses, and invoice calculations in one auditable process.

> “With Nace, we were able to review **10,000 invoices** end to end, strengthening our billing workflow and surfacing meaningful revenue leakage that would have been hard to catch manually.”
>
> April Hensen, CEO, Barton Associates

## When every assignment has different billing rules

[Barton Associates](https://www.bartonassociates.com/) is a locum tenens staffing agency serving healthcare facilities across all 50 states and U.S. territories. Its network spans more than 120 practice areas.

Every assignment comes with unique billing terms. Rates, overtime rules, holiday pay, reimbursable expenses, and special provisions vary by contract. This creates multiple points for pre-billing errors:

- Incorrect base or overtime rates
- Unbilled or misapplied holiday pay rules
- Reimbursable expenses charged outside contract terms
- Uncaptured shift hour variances or duplicate charges
- Contract-specific provisions missed during manual review

Across high invoice volumes, catching these discrepancies manually is nearly impossible, resulting in delayed payments and revenue leakage.

## Turning contracts into automated, auditable billing logic

**Contract + timesheet + expenses → automated verification → evidence → invoice.**

Barton moved contract verification into the billing process itself.

Nace works on top of existing ATS, VMS, and ERP systems, adding verification and reasoning without requiring teams to replace their core systems.

As timesheets and expense reports come in, Nace agents check each line item against the corresponding assignment. Rates, overtime rules, expenses, holiday pay, and other provisions are verified against the contract before the invoice reaches review.

The evidence stays connected to the calculation. Each invoice includes an audit trail showing the source data, the contract terms applied, and how the charge was calculated. Individual line items can be traced back to the relevant timesheet entry and contract clause.

Work that previously took hours or days can now be completed in seconds, while the team can review billing across thousands of invoices without losing the connection to the underlying documents.

![An invoice beside its audit trail. A lodging line is checked against the contract in three steps: lodging approved and receipt amount pass, the dates fail because the stay starts three days after the contract ends, and both dates are shown cropped from the placement order and the receipt.](https://nace.ai/images/customers/barton-associates/audit-trail.webp)

## What changed in the first eight weeks

Barton evaluated performance across 10,000 invoices reviewed end to end during the first eight weeks after launch, compared with the eight weeks before:

| Measure                                          | Change       |
| :----------------------------------------------- | :----------- |
| Invoice disputes and adjustments                 | 52% fewer    |
| Time from work week end to invoice submission    | 50% faster   |
| Days sales outstanding                           | 14.05% lower |
| Net accounts receivable at the end of the period | 12.20% lower |
| Invoice accuracy rate                            | 1.47% higher |
| Time spent per user, each week                   | 15% saved    |

## Billing built around the contract

For agencies, billing often depends on information spread across contracts, timesheets, expenses, and supporting documents. Nace brings those inputs into one workflow, keeping each invoice connected to the terms and evidence behind it.

Teams can handle higher billing volume with less manual reconciliation while maintaining a clear, auditable record of every charge.

## Bring us one contract, timesheet and invoice

We'll map what can be automated, show how Nace integrates with your existing ATS and ERP systems, and project your expected ROI.

- [Contact sales](https://nace.ai/contact?source=customer-story)

## For agents

- [Drex API guide](https://nace.ai/drex.md): the decision model: request shape, question types, benchmarks and deployment, as markdown
- [Decision endpoint](https://console.nace.ai/v1/systemone): POST with model "drex-latest", a state string and typed questions (choice, noul, score); https://console.nace.ai/v1/models lists checkpoints
- [Document endpoints](https://console.nace.ai/v1/documents/{parse|split|classify|extract|ground}): POST a source (a public URL, an uploaded workspace file or a finished parse job) and poll GET https://console.nace.ai/v1/documents/jobs/{id}; the same key and credit as decisions
- [Console](https://console.nace.ai): API keys, the playground, usage and billing; send `Authorization: Bearer $NACE_API_KEY` on every request
- [Console docs](https://console.nace.ai/docs): quickstart, question types, the document routes, errors, limits and pricing
- [Nace Document Intelligence](https://nace.ai/ndi.md): the Perception series: parse, split, classify, extract and ground any file type with a location on every value
- [Developers](https://nace.ai/developers.md): Console: what it holds, a scripted agent session, the ways in and the four deployment boundaries, from our managed cloud to air-gapped
- [Site index](https://nace.ai/llms.txt): every page on nace.ai; append `.md` to any page URL or send `Accept: text/markdown` for the markdown version