Pre-built APIs for connecting OnAccount to the systems that run your operation.
Most finance teams work alongside operational systems they did not choose and would not replace. Connecting those systems to finance has usually meant a bespoke build for each one, paid for and maintained on its own. The OnAccount API library changes what that job takes.
What is it?
The OnAccount API library is a set of pre-built APIs that are available with the standard OnAccount product and stay under our maintenance. Instead of commissioning a bespoke integration for each system you want to connect, your project connects into a contract that already exists, has already been security reviewed, and is already in production with other customers.
The library covers the connection points most operations need:
- Sales and purchases
- Journals
- Users
- Customer and supplier accounts
- Account balances
- Statement downloads
Endpoints are versioned, so an integration built today keeps working as OnAccount grows. Where your business needs something particular, we customise the standard APIs rather than starting again from scratch.
As an example, one OnAccount customer now runs three integrations on the standard sales and purchase APIs, covering driver payment transactions, warehouse data and sales invoices from three different systems. Each went live in a matter of days rather than weeks.
Why does it matter?
- Significantly faster and more cost-effective. The groundwork already exists, so a connection is a configuration exercise rather than a development project. Time and cost can be reduced by up to 75% of custom API builds.
- Security is maintained centrally. We engineer and review authentication, input validation and access control for the whole library, and every integration built on it inherits that work. A custom API needs its own security review every time you build one.
- Far less month-end reconciliation. Transactions post in real time, and the library validates them before they land, so there is no overnight batch to chase and no duplicate data.
- Management by exception. Your team looks at what genuinely needs a person instead of confirming the thousands of transactions that already matched, and that holds as volumes grow.
- Two-way visibility between finance and operations. Drill back from a posted transaction to the operational record behind it, or surface account and statement information where your operational people already work.
- Lower cost with each additional integration. The second and third integrations reuse what the first one paid for, while a custom approach repeats much of its original cost each time.
- Financial data that stands up to an audit. Double-entry rules, tax treatment and currency handling are built in, idempotency means a repeated request only counts once, and everything runs through one audit trail and one permission model
Who is it for?
- Organisations with operational systems worth keeping. A transport system, a warehouse system, an ERP or something built in-house years ago. You keep what works and connect OnAccount to it.
- High-volume operations with complex billing. Where finance has to keep pace with the operation rather than reconcile it after the fact.
- Finance teams still moving data by hand. Manual journals, spreadsheet exports and month-end matching are the clearest signs that a connection would pay for itself.
- Your other vendors and integration partners. They build against a documented contract that already exists, which means less work on their side and less coordination on yours.
If you need one narrow integration, once, and expect nothing to follow it, a custom build may be all you need. For everyone else, the library is the faster and cheaper path.
How does it work?
- It runs system to system over the standard APIs. No file drops, no manual re-keying, no room for a transposition error between two screens.
- Everything is validated before it posts. The library models each transaction and checks it against OnAccount's own accounting rules, so problems surface before they hit the ledger rather than after.
- Data flows in real time or on a schedule. Pick events as they happen for near real-time visibility, or a cadence that suits how your operation runs.
- One source of truth for masterdata. Update a customer once and every connected system agrees from that point on.
- Built to fail safely. Retry logic handles dropped connections, rate limiting protects the system under load, and every error traces back to the record that caused it.
- Supported as part of the standard product. Our team maintains and tests the library alongside the rest of OnAccount, so upgrades are our problem rather than yours.
Getting started
Tell us which systems you need to connect and what data has to move between them. We will show you which standard APIs cover it, what would need customising, and what the work realistically looks like.
