INTEGRATIONSTWINFIELDTwinfield integration
A Twinfield integration means invoices, customers and payments no longer move between systems by hand. For accounting firms and organisations with several administrations, the main saving is checking work at the end of the period. Below you'll read how the Twinfield API works and where integrations tend to get stuck in practice.
ISO 9001 & 27001
- Sales invoices and sales transactions goes back and forth with Your other systems
- Customers and suppliers as dimensions goes back and forth with Your other systems
- Open items goes back and forth with Your other systems
- Purchase transactions goes back and forth with Your other systems
Built for clients including Tata Steel, M&G Investments, Digistore24, Toppers in Concert, Bar-le-Duc and Loogman
This is the data organisations most often let flow between systems. Which of it matters to you depends on where work is getting stuck today.
Sales invoices and sales transactions
Twinfield can create a sales invoice itself, or you post an invoice from another system as a sales transaction. Which of the two is possible also depends on the Twinfield package the administration uses.
Customers and suppliers as dimensions
In Twinfield, customers (debtors) and suppliers (creditors) are called dimensions. Level 1 holds general ledger accounts, level 2 customers, suppliers and cost centres, level 3 projects and assets. An integration has to know this structure to post entries in the right place.
Open items
Which invoices are still outstanding and for how long. This is the information sales, service and account managers ask for most often, and rarely look up in Twinfield themselves.
Purchase transactions
Supplier invoices, with general ledger account, VAT code and, where needed, a cost centre or project.
Bank statements and matching
Reading in electronic bank statements and matching payments to open items. Twinfield has separate web services for this, so an integration can take over the matching too.
For each combination: which data moves back and forth, what the standard integration does and what to watch out for.
- Connect Twinfield to HubSpotConnect Twinfield to HubSpot: which data moves between CRM and accounting, which system leads, and where VAT, codes and API limits go wrong in practice.
- Connect Twinfield to SalesforceConnect Twinfield to Salesforce: won opportunities become invoices in the right administration, and open items come back to your account team in Salesforce.
Not always. If an existing integration for Twinfield does exactly what you need, we'll tell you.
Twinfield integrations come from parties that have completed Wolters Kluwer's certification process. An integration like that has been assessed on how it is built and how it works. For common combinations something often exists already; your accountant or the vendor of the other package usually knows which integrations are available.
A standard integration is enough if data flows one way, you work with a single administration and the posting logic matches what your accountant wants. As soon as you need several administrations, your own dimensions or feedback to sales, standard integrations more often only half fit.
- You work with several administrations within one organisation, such as a holding company with operating companies, and every entry has to land in the right administration.
- You use cost centres or projects that have different names or a different structure in the source system.
- Your CRM, platform or own software has no certified Twinfield integration.
- Financial data needs to go back to sales or service, such as open items per customer.
- You process large numbers of lines and need to summarise them to stay within the limits and fair-use rules.
SOAP web services with XML
Twinfield mainly works with SOAP web services. Through the ProcessXml service you send XML messages for transactions, dimensions, sales invoices and VAT codes, among other things. There are also separate services for searching (Finder), matching (Matching), periods and deleted transactions. Webhooks aren't in the documentation: an integration requests changes itself.
OpenID Connect and the right administration
You register your application in the Twinfield developer portal and get tokens through OpenID Connect and OAuth 2.0. With the offline_access scope you also get a refresh token. In every SOAP call you include the access token and the code or ID of the administration. From the token information you also get the cluster the organisation runs on.
Limits in API credits
A read request costs 1 credit, any other request 3. Per IP address, per client and per organisation there is a maximum of 1,000 credits per minute, and 500 per combination of client and organisation. For a new client that isn't certified yet, the per-client limits are 5 per cent of that. A client may make at most 20 requests at the same time, and 10 per organisation. Twinfield doesn't offer higher limits.
Certification and test environment
Anyone who wants to integrate with Twinfield takes out an API certification subscription with Wolters Kluwer. It gives you access to the developer portal, your own test environment, technical support and an audit of your integration.
Limits on messages
A transaction may have at most 1,000 lines; Twinfield recommends no more than 500. Under its fair-use rules, Twinfield watches the number of transaction lines, invoice lines and dimensions an integration creates, and may ask the user to reduce them.
An integration moves data. In between, AI can read, sort and prepare a suggestion. Where it matters, a person decides.
Suggested entries for purchases
AI reads a purchase invoice and suggests the entry: supplier, general ledger account, VAT code and, if relevant, cost centre or project, with a short explanation why. A team member or accountant approves the suggestion. Only then does the entry go to Twinfield.
Flagging across administrations
For an accounting firm, AI can check per period which administrations stand out: missing bank statements, unusual VAT codes or a customer whose open items are rising sharply. The result is a worklist for a person, not an automatic correction.
Payment behaviour in plain language
A short summary of a customer's open items, so an account manager without Twinfield access knows what's going on. You decide who may see which data.
VAT rounding differences
Twinfield calculates VAT per line and carries rounding differences over to the next line. The total can therefore differ by a cent from your source system. Send the VAT per line, as Twinfield itself recommends, or let Twinfield correct differences of up to 0.01 with autobalancevat.
Low limit during development
For a client that isn't certified yet, the per-client limits are 5 per cent of the normal number of API credits. A first full import or a test with real volumes quickly gets stuck as a result. Plan certification early in the project.
Package level
Not every Twinfield package supports the same web services. Creating sales invoices through the API isn't possible in Extra Boekhouden and Basis Boekhouden; there you post a sales transaction. Projects and cost centres are missing in Basis Boekhouden.
Codes and masks
Twinfield uses masks for the codes of transactions and master data, and only a superuser can change them. So a customer number from your CRM isn't automatically a valid customer code. Agree beforehand which code the integration uses.
What goes where
Which data moves, in which direction, and which system wins when two values differ. That is written down before anything gets built. For this integration, that means: Sales invoices and sales transactions, Customers and suppliers as dimensions, Open items, Purchase transactions, Bank statements and matching.
Fields and rules
For every field, how it translates between the systems: statuses, VAT codes, general ledger accounts, item numbers. And what happens with a duplicate or a missing value. For this integration, that means: SOAP web services with XML, OpenID Connect and the right administration, Limits in API credits, Certification and test environment, Limits on messages.
Testing with real cases
In a sandbox or test administration, with the exceptions you actually run into: credit notes, partial deliveries, changed customer details.
Live, with logging and monitoring
Every sync is logged, and when something fails, someone gets an alert. If a vendor changes its API, we update the integration.
No account manager. You talk to someone who builds integrations themselves, and who will tell you when a standard integration is enough.
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- ISO 9001 and ISO 27001, certified by Kiwa
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Does Twinfield have a REST API?
Twinfield mainly works with SOAP web services and XML messages, for example through the ProcessXml service. Authentication runs through OpenID Connect and OAuth 2.0. You send the access token and the administration code in the header of every SOAP call.
Is there a test environment for Twinfield?
Yes, as part of the API certification subscription that Wolters Kluwer requires for parties that integrate. It gives you your own test environment, so you don't have to test in a client's administration. Technical support and an audit of the integration are included too.
What are the Twinfield API limits?
Twinfield counts in credits: a read request costs 1, any other request 3. Per IP address, per client and per organisation you may use 1,000 credits per minute, and 500 per combination of client and organisation. If you go over, you get status 429 with a Retry-After header telling you when you can continue.
Can I create invoices through the API with any Twinfield package?
No. According to Twinfield's function overview, creating sales invoices through the API isn't possible in Extra Boekhouden and Basis Boekhouden. Sales transactions, customers and suppliers, and bank entries are possible in all packages. So check first which package your administration has.
Why is the VAT in Twinfield a cent off from my invoice?
Twinfield calculates and rounds VAT per line, and carries the rounding difference over to the next line. With many lines, the total can differ by a cent from a calculation over the total amount. Send the VAT amounts per line or switch on autobalancevat.
Does Twinfield have webhooks?
Twinfield's API documentation doesn't list webhooks. So an integration requests changes itself, for example at set times through searches and the service for deleted transactions. Keep the per-minute limits in mind when you do.
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- Moneybird integrationDutch online accounting package for business owners, freelancers and online stores, with invoicing, purchases, banking and VAT returns in one place.
- SnelStart integrationDutch accounting software for SMEs and their bookkeepers, from invoices and VAT returns to orders and stock.
Sources
The technical facts on this page come from the vendors' official documentation, checked on 19 September 2026. Vendors change their APIs and limits; when we build an integration, we always check the current state.