Sage Accounting (formerly Sage Business Cloud Accounting and Sage One) is Sage's cloud-based accounting software for UK and international small and medium businesses, covering invoicing, expenses, banking, VAT, payroll integration, and financial reporting. Its REST API at https://api.accounting.sage.com/v3.1 provides programmatic access to contacts, sales and purchase invoices, ledger accounts, journals, tax rates, bank accounts, and attachments. Authentication uses OAuth 2.0 with the authorization endpoint at https://www.sageone.com/oauth2/auth/central and the token endpoint at https://oauth.accounting.sage.com/token; access tokens expire after five minutes and refresh tokens after 31 days, and the X-Business header selects the target business.
Sage Accounting is listed with 1 API on the APIs.io network. Tagged areas include Accounting, Bookkeeping, Invoicing, Small Business, and VAT.
Sage Accounting’s developer surface includes engineering blog, documentation, pricing, signup flow, support, and 9 more developer resources.
Regulatory Posture applies to this provider. Its tags matched the
Horizontal (data, software, accessibility, platform) regime, so
Regulatory Posture carries 15 points of the composite.
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Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for
this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero:
never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and
several others — scorable at all.
The six quality facets above are damped to 85 points between them,
because the conditional facet above carries the other
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Agent readiness — checks not met, largest first (exact, from this profile):
Idempotency+9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics+8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card+8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
12 more unmet checks in the Agent Readiness table above.
Kin Score — facets with the most composite points still available (weight × headroom):
Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.
aid: sage-accounting
name: Sage Accounting
description: Sage Accounting (formerly Sage Business Cloud Accounting and Sage One) is Sage's cloud-based accounting software
for UK and international small and medium businesses, covering invoicing, expenses, banking, VAT, payroll integration, and
financial reporting. Its REST API at https://api.accounting.sage.com/v3.1 provides programmatic access to contacts, sales
and purchase invoices, ledger accounts, journals, tax rates, bank accounts, and attachments. Authentication uses OAuth 2.0
with the authorization endpoint at https://www.sageone.com/oauth2/auth/central and the token endpoint at https://oauth.accounting.sage.com/token;
access tokens expire after five minutes and refresh tokens after 31 days, and the X-Business header selects the target business.
type: Index
deliveryModel:
model: saas
open_source: false
commercial: true
callable_host: false
label: Hosted service · you call their endpoint
confidence: medium
source:
- pricing
generated: '2026-08-28'
method: derived
accessModel:
pricing: unknown
onboarding: unknown
trial: false
try_now: false
public: false
label: Unknown
confidence: low
source:
- security
generated: '2026-11-06'
method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/sage-accounting.png
tags:
- Accounting
- Bookkeeping
- Invoicing
- Small Business
- VAT
- Sage
- United Kingdom
- OAuth
- Authentication
tags_raw:
- Accounting
- Bookkeeping
- Invoicing
- Small Business
- VAT
- Sage
- UK
- OAuth 2.0
- Authentication
url: https://raw.githubusercontent.com/api-evangelist/sage-accounting/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-11'
specificationVersion: '0.23'
apis:
- aid: sage-accounting:accounting-api
name: Sage Accounting v3.1 REST API
description: REST API for Sage Business Cloud Accounting providing access to contacts, sales invoices, sales credit notes,
purchase invoices, purchase credit notes, ledger accounts, journals, products, services, tax rates, bank accounts, bank
transactions, and attachments. Multi-business apps target a business via the X-Business header.
humanURL: https://developer.sage.com/accounting/reference/
baseURL: https://api.accounting.sage.com/v3.1
tags:
- Accounting
- REST API
- OAuth
- Small Business
- Authentication
tags_raw:
- Accounting
- REST API
- OAuth 2.0
- Small Business
- Authentication
properties:
- type: Documentation
url: https://developer.sage.com/accounting/reference/
- type: Authentication
url: https://developer.sage.com/accounting/guides/authenticating/authentication
- type: Guides
url: https://developer.sage.com/accounting/guides/
- type: Authorization Endpoint
url: https://www.sageone.com/oauth2/auth/central?filter=apiv3.1
- type: Token Endpoint
url: https://oauth.accounting.sage.com/token
- type: ChangeLog
url: https://developer.sage.com/accounting/reference/changelog/
common:
- type: VulnerabilityDisclosure
url: security/sage-accounting-vulnerability-disclosure.yml
- type: DomainSecurity
url: security/sage-accounting-domain-security.yml
- url: https://www.sage.com/en-gb/blog/feed/
type: Blog
- type: GitHubOrganization
url: https://github.com/Sage
- type: LinkedIn
url: https://www.linkedin.com/company/sage-software
- type: Website
url: https://www.sage.com/en-gb/products/sage-accounting/
- type: DeveloperPortal
url: https://developer.sage.com/accounting/
- type: Documentation
url: https://developer.sage.com/accounting/reference/
- type: Guides
url: https://developer.sage.com/accounting/guides/
- type: Pricing
url: https://www.sage.com/en-gb/products/sage-accounting/pricing/
- type: Signup
url: https://developer.sage.com/accounting/guides/getting-started/
- type: Support
url: https://www.sage.com/en-gb/support/
- type: StatusPage
url: https://status.sage.com
- type: Community
url: https://www.sagecity.com
features:
- name: Sales and Purchase Invoicing
description: Create and manage sales invoices, sales credit notes, quotes, estimates, purchase invoices, and purchase credit
notes with line items, VAT rates, and attachments.
- name: Contacts
description: Manage customer and supplier records with addresses, default tax treatment, payment terms, and credit limits.
- name: Ledger and Journals
description: Read the chart of ledger accounts and post journal entries directly for bookkeeping automation and GL integration.
- name: Banking
description: Bank accounts, bank transactions, transfers, and reconciliation flows with attachment support.
- name: VAT and Tax
description: Tax rates, VAT schemes (Standard, Cash, Flat Rate), and HMRC Making Tax Digital (MTD) VAT submission support.
- name: Attachments
description: Upload and attach files (receipts, invoices) to transactions and contacts via the Attachments API.
solutions:
- name: SMB Accounting Integration
description: Sync invoices, contacts, and payments between Sage Accounting and CRM, e-commerce, or billing platforms used
by UK small businesses.
- name: Practice and Bookkeeper Tools
description: Power tools used by accountants and bookkeepers to manage many client Sage Accounting businesses from one interface.
- name: Making Tax Digital
description: Submit VAT returns to HMRC directly from integrated apps using the MTD-compliant Sage Accounting API.
useCases:
- name: E-commerce Order Sync
description: Push Shopify, WooCommerce, or Amazon orders into Sage Accounting as sales invoices with VAT, customers, and
bank receipts.
- name: Expense Management
description: Create purchase invoices and attach receipts from expense tools like Dext or AutoEntry for AP automation.
- name: Multi-Business Reporting
description: Aggregate financial data across many Sage Accounting businesses for group-level reporting and dashboards.
integrations:
- name: Stripe
description: Reconcile Stripe payouts and charges against Sage Accounting invoices
- name: GoCardless
description: Direct Debit collection with reconciliation back to Sage
- name: Shopify
description: Push Shopify orders into Sage Accounting as sales invoices
- name: Dext
description: Receipt and invoice capture pushed into Sage Accounting
- name: HMRC MTD
description: Submit Making Tax Digital VAT returns directly to HMRC
maintainers:
- FN: Kin Lane
email: kin@apievangelist.com
x-parent: sage
x-relationship: product
Sage Accounting API — frequently asked questions
Does Sage Accounting have an API?
Yes. APIs.io lists 1 API from Sage Accounting, including Sage Accounting v3.1 REST API.
How do I authenticate with the Sage Accounting API?
Sage Accounting uses bearer-token authentication.
Is the Sage Accounting API ready for AI agents?
Sage Accounting has a Kin Score of 22.0 out of 100 (emerging) and an Agent Readiness score of 2.5 (human-only), scored by API Evangelist on 2026-11-06.
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