Treasury APIs
The bank knows where the cash is. The ERP knows what it is for and when it is due. How treasury software connects to both, and where each API fits.
Bank APIs
Each bank’s corporate API
Citi
HSBC
Bank of America
Deutsche Bank
Danske Bank
Your product
Treasury software
- Cash positioning
- Forecasting
- Payments
- Reconciliation
ERP APIs
The company’s books
NetSuite
Business Central
SAP S/4HANA Cloud
Sage Intacct
Xero
One Apideck Accounting API for 55+ ERPs and accounting platforms
What is a treasury API?
A treasury API is an interface treasury software uses to see and move a company’s cash. Corporate treasury runs on two kinds: bank APIs for balances, statements and payments, offered by each bank as a corporate or premium API, and ERP and accounting APIs for open payables and receivables, the ledger and the journal entries treasury writes back. A treasury management system needs both: the bank shows the cash, the books show what it is committed to.
Looking for US government data, such as the national debt or Treasury rates? That is the US Treasury’s public Fiscal Data API, a different thing from corporate treasury APIs.
The two sides of a treasury integration
Every cash movement exists twice: once at the bank, once in the books. Treasury software reads both and keeps them in step.
Bank APIs
- Data
- Balances, intraday and end-of-day statements, payment initiation and status, virtual accounts, FX.
- Source
- Each bank’s corporate API, often sold as a paid “premium” API, or host-to-host and SWIFT connections.
- Answers
- How much cash is there, in which account, right now? Did the payment go out?
- Examples
- J.P. Morgan, Citi, HSBC, Deutsche Bank, Danske Bank, Rabobank
ERP and accounting APIs
- Data
- Open bills and invoices, payments, ledger accounts, journal entries, aged payables and receivables, bank accounts as the books see them.
- Source
- The company’s ERP or accounting platform, such as NetSuite, Microsoft Dynamics 365 Business Central, SAP, Sage Intacct, Xero and QuickBooks.
- Answers
- What will come in and go out, and when? How was each cash movement booked, and to which entity?
- Examples
- Apideck Accounting API, or each platform’s own API
Which banks sell corporate and treasury APIs, and what each one covers (payments, virtual accounts, account validation, real-time payments), is tracked on the Open Banking Tracker’s list of premium and corporate banking APIs, an Apideck project.
What treasury needs from the bank and from the ERP
No treasury workflow runs on bank data alone. Each one needs a second half from the books.
| Treasury task | From the bank API | From the ERP API |
|---|---|---|
| Cash positioning | Current and intraday balances per account | Which entity and ledger account each bank account belongs to |
| Cash forecasting | Today’s opening balance | Open receivables by due date, open payables by due date, recurring journal entries |
| Payments | Send the payment and track its status | Read the approved bills to pay, then mark them paid in the ledger |
| Reconciliation | Statement lines (camt.053 under ISO 20022, or MT940) | The payments, invoices and bills to match them against |
| Bank fees, interest and FX | The charges and rates on the statement | Journal entries that book them to the right accounts |
| Intercompany and in-house bank | Transfers between group accounts | Matching entries in each entity’s books |
A cash forecast needs both APIs
The bank gives you one number: what is in the account today. Everything after today comes from the books. Open invoices, by due date, are the cash coming in. Open bills, by due date, are the cash going out. Roll them forward week by week from the bank’s opening balance and you have a forecast.
Without the ERP, a treasury product can only report the past. With it, it can tell a finance team which week the balance dips, before it does.
8-week cash forecast
ExampleToday, from the bank
$1.24M
Week 8, forecast
$1.02M
W1
1.29
W2
1.05
W3
1.12
W4
1.23
W5
1.00
W6
1.07
W7
1.16
W8
1.02
Closing balance, $M
- Opening balanceBank API
- Receivables by due dateERP API
- Payables by due dateERP API
How to integrate bank APIs and the ERP for treasury
The same four steps, whether you build a treasury management system or add treasury features to a payments or banking product.
- 1
Connect the banks
Each bank exposes its own corporate API, with its own onboarding, certificates and contract. Larger groups add host-to-host or SWIFT for banks without an API. Payment and statement formats increasingly follow ISO 20022 (pain.001 out, camt.053 back).
- 2
Connect the ERP
Every ERP has a different API and data model. A treasury product sold to many companies meets NetSuite at one customer and Business Central or Xero at the next, which is where a unified accounting API saves a build per platform.
- 3
Map accounts and entities
Link each bank account to its ledger account and legal entity, once per customer. Everything after this, forecasting, reconciliation and posting, depends on that map.
- 4
Read, decide, write back
Read balances from the bank and open items from the ERP, forecast and decide, send payments through the bank, then write the results to the books: payments against bills, journal entries for fees, FX and intercompany.
Open banking and corporate bank APIs are not the same product. The Open Banking Tracker explains the difference in open banking vs premium banking APIs.
Where Apideck fits
Apideck covers the ERP side of treasury. The Accounting API reads and writes bills, invoices, payments, ledger accounts, journal entries and reports across 55+ accounting platforms and ERPs, including NetSuite, Business Central, Xero and QuickBooks, through one data model and one authorization flow. Aged payables and aged receivables come back in the same format on every platform that supports them, which is the input a cash forecast needs.
Apideck does not connect to banks, send payment files or read a company’s bank accounts. Treasury and payment platforms use it next to their own bank connections: the bank API moves and reports the cash, the Accounting API keeps the books in step. Cloud connectors pass data through in real time with zero data retention, so no copy of your customers’ books sits on Apideck infrastructure.
Authorization: Bearer <APIDECK_API_KEY>x-apideck-app-id: <APP_ID>x-apideck-consumer-id: <CUSTOMER_ID>// 200: open bills per supplier, by due date{ "report_as_of_date": "2026-11-13", "period_length": 30, "outstanding_balances": [{ "supplier_name": "Northwind Logistics", "outstanding_balances_by_currency": [{ "currency": "EUR", "total_amount": 48200, "balances_by_period": [{ "start_date": "2026-11-14", "end_date": "2026-12-13", "total_amount": 48200, "balances_by_transaction": [{ "transaction_type": "bill", "transaction_number": "BILL-2291", "due_date": "2026-11-28", "outstanding_balance": 48200 }] }] }] }]}
The same three calls on NetSuite, Business Central, Xero and every other connected ERP. Example values.
Before you build a treasury integration
- Which banks your customers actually use, and whether each offers a corporate API, host-to-host or only file exports.
- Which ERPs your customers run, by country: NetSuite, Business Central and SAP for mid-market and enterprise, Xero and QuickBooks for smaller groups.
- Multi-entity support: subsidiaries, currencies and intercompany in the ERP data model.
- Write support for the records treasury creates: payments, journal entries, bank accounts.
- Real-time reads for positions and forecasts, not a nightly copy.
- Where financial data is stored, and by whom. Treasury and finance teams will ask in the security review.
- A hosted authorization flow, so neither you nor your customer shares ERP credentials.
Treasury API FAQ
- What is a treasury API?
- A treasury API is an interface that treasury software uses to see and move a company’s cash. In corporate treasury the term covers two kinds of API. Bank APIs return balances and statements and send payments, from each bank the company works with. ERP and accounting APIs return the company’s open payables and receivables, ledger accounts and journal entries, and accept the entries that treasury writes back. A treasury management system needs both. The term is also used for the US Treasury’s public Fiscal Data API, which publishes government financial data and is unrelated to corporate treasury.
- What is a treasury management API?
- Treasury management API usually means a bank’s corporate treasury API: the service a bank sells to its business customers to report balances, initiate payments and manage accounts programmatically, such as J.P. Morgan’s or Citi’s treasury APIs. It can also mean the API of a treasury management system (TMS) itself. Either way, a TMS has to connect to the ERP to know what is owed and what is due, which is the part the bank API does not cover.
- How do you integrate bank APIs with an ERP for treasury?
- Connect each bank through its corporate API (or host-to-host where there is no API), connect the ERP through its API, and map each bank account to its ledger account and entity. Then read balances and statements from the bank, read open bills and invoices from the ERP, and write results back to the ERP: payments against bills, and journal entries for fees, interest, FX and intercompany. Treasury software sold to many companies typically uses a unified accounting API for the ERP side, so one integration covers NetSuite, Business Central, Xero and the rest.
- Which banks offer treasury APIs?
- Most large corporate banks do, including J.P. Morgan, Citi, Bank of America, Wells Fargo, HSBC, Deutsche Bank, Goldman Sachs, ING, Rabobank, Danske Bank and Nordea. Many charge for them, which is why they are often called premium APIs, unlike the free account access that open banking regulation requires. The Open Banking Tracker, an Apideck project, lists the banks with corporate and treasury APIs and what each API does.
- What is the difference between open banking APIs and treasury APIs?
- Open banking APIs give regulated, consent-based access to account data and payment initiation, under rules such as PSD2 in Europe, and are built mainly for third-party apps. Corporate treasury APIs are commercial products a bank sells to its own business customers, with features open banking does not cover: bulk and cross-border payments, intraday reporting, virtual accounts, FX and liquidity management. Treasury teams usually use the bank’s corporate API.
- Does Apideck provide bank connectivity for treasury?
- No. Apideck does not connect to banks, send payment files or read a company’s bank accounts. It covers the ERP side: the Accounting API reads and writes bills, invoices, payments, ledger accounts and journal entries across 55+ accounting and ERP platforms through one integration. Treasury and payment software uses it next to its bank connections.
- What is ISO 20022 and why does it matter for treasury APIs?
- ISO 20022 is the global standard for financial messages. Treasury uses two of its messages most: pain.001 to send payment instructions to a bank and camt.053 for end-of-day bank statements, which replace older formats such as MT940. Bank APIs increasingly carry these messages, which makes statements from different banks easier to reconcile against the ERP.
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