There are three levels on which you can connect something to sevDesk, and the order you work through them decides how much effort it takes. The first level is already in your account: bank connection, access for your tax firm including the DATEV export, filing the advance VAT return with the tax office. All you need for those is your login. The second level is integrations you book under Erweiterungen (extensions): Shopify for your own shop, Billbee as a bridge to Amazon and eBay, plus time tracking, CRM and payment services. The third level is the REST API, the programming interface for your own software. It is the only route that requires programming skills, and it hangs on the Buchhaltung Pro plan: for that plan the pricing page showed a list price of 34.90 euros net per month with monthly billing when it was retrieved on 20 September 2026, struck through in favour of a running discount campaign. So the rule of thumb is: check the two lower levels first. You reach for the API when your own software is supposed to create contacts, quotes or invoices inside sevDesk.
One thing up front, because it belongs here: I do not run sevDesk, I run Lexware Office, and my AI employee works on that system's interface. What that looks like is in Lexoffice Integration: The Main Routes, and the path from inbox to finished draft is in AI Agent for Bookkeeping and Inbox. This article describes sevDesk the way the vendor documents it, and shows at the end how the same workflow is reachable through an adapter you build yourself. The concept behind it is at Hiring an AI employee.
Level 1: What is already in your account
Three connections you do not have to buy on top; they belong to the paid plans.
The bank account. According to the pricing page, the online banking link is included from the Buchhaltung plan upwards, and sevDesk states that it supports more than 4,000 banks and neobanks. That is how transactions land in the account and payments can be matched to invoices.
The tax firm. You invite them with their email address, either under Erweiterungen and Integrationen or via Steuern and "Mein Steuerberater". The firm sets up its own login in the free tax adviser portal and, according to the help article, receives real-time access to all of your booking-relevant data, can pull the DATEV export and reports itself, and can correct ongoing entries. The article names no way to limit that access to individual areas. So treat the invitation for what it is: a deliberate release to a contractual partner, not a small checkbox in the settings.
The route to the tax office and to the firm's software. The advance VAT return can be filed directly from sevDesk with the tax office, via "Überprüfen und Versenden". For the firm, the integration directory names the DATEV Rechnungsdatenservice, ADDISON OneClick and steuerberaten.de, and the pricing page lists the DATEV and ADDISON export in all paid plans. Which of these routes is the right one is not something the software tells you, it is something your tax firm tells you.
Level 2: Integrations you book
The partner directory sorts connections into fourteen categories, among them banking, CRM, e-commerce, trades, productivity, time tracking and tax. This is where most cases end without anyone writing code.
For retail there is one point worth knowing, because people often expect otherwise: Shopify is listed as its own integration, while Amazon and eBay come in through Billbee, Etsy through Billbee or Kassenklingeln, and Stripe through miraclesync. So the marketplace does not hang on sevDesk directly, it hangs on an intermediary that collects orders and builds invoices from them. What that means in practice, above all for the question of who notices when an order never arrives, is in Automating Marketplace Invoices in Germany.
Three questions are worth asking before any integration. Does the service only read, or does it also write? Where does the invoice number come from, and does it come from exactly one place? And who keeps the connection working when one side changes something? With a booked integration that is the provider, with one you built yourself, you.
Level 3: The programming interface
A programming interface is a door for programs instead of people. Instead of clicking "new invoice" in the browser, your software sends a message to an address at sevDesk and gets an answer back. Four terms are enough to follow the conversation.
- Endpoint: the address for a particular thing. The base address is
https://my.sevdesk.de/api/v1, and the resource comes after it: /Contact for contacts, /Invoice for invoices, /Order for quotes.
- API token: a long password your program identifies itself with. At sevDesk it is a string of 32 characters, sent in the header of every request.
- Status code: the short answer telling you whether it worked. 200 means done, 201 means created, 401 means a wrong or missing token, 403 means no permission.
- Document status: the number saying how far along a document is. In sevDesk 100 means draft, 200 means sent or open, 1000 means paid.
Quotes, by the way, are not called quotes in the interface but orders, distinguished by a short code: AN for the quote, AB for the order confirmation, LI for the delivery note. Quotes have their own stations too, among them 300 for rejected and 500 for accepted, and if you want to turn one into an invoice later, there is a dedicated call for it.
You find the token under Erweiterungen and Integrationen in the area "API-Token für Integrationen", and depending on your plan also under Erweiterungen and API.
Where sevDesk and Lexware Office differ
Both tools solve the same job, but in three places that matter for automation they are built differently. The Lexware side is covered in Lexoffice Integration: The Main Routes.
The price is the snapshot from the day it was retrieved; plans and campaigns change. The middle three rows are the real difference day to day: the sevDesk token knows no fine-grained permissions, and connected software can not only create an invoice but drop it straight into the customer's inbox through the send call. Convenient, and exactly why the next section matters.
The token is as sensitive as access to your bank account
To sevDesk, a program holding your token is indistinguishable from you. It can read contacts, create documents and send invoices. And because the token has an unlimited lifetime, one that goes astray will not quietly expire at some point.
Where it belongs. The token is a password and gets treated like one: password manager instead of document, environment variable instead of source code. The three places it ends up in practice and must not are the chat log with the developer, the email with the subject line "credentials", and the public code repository.
How to narrow access. The documentation does not provide for per-token permissions, so you work with what exists. According to the specification every administrator has exactly one token, and additional users are bookable as an add-on, at 5.90 euros per month according to the pricing page, described there as users "mit definierten Zugriffsrechten" (retrieved 20 Sept 2026). A separate login for the connection therefore buys you attribution and a switch: you can see who created what, and you can shut that one access down without touching your own. What it does not buy you is a limit on permissions. The token hangs on the administrator according to the specification, and an administrator may do everything. So do not mistake this setup for the principle of least privilege, where an access can only do what its job requires. The published interface does not offer that, which is why something else carries the weight here.
Your emergency exit. A new token can be generated and confirmed with your password; the old one then stops working. Two things belong with that. The token is not shown again after it has been created, so copy it into place right away. And the documentation explicitly says not to delete the associated user, because the token hangs on them.
Why the draft is the safe way to start. A document with status 100 is a draft and still editable; from 200 it counts as sent. The important part: status is a mandatory field when creating an invoice, so it does not appear by itself, your software sets it. Which means it could just as easily write 200 straight away. On top of that comes the clearest warning in the whole documentation: the mail send call automatically marks the invoice as sent, and sevDesk notes that in production it may not be changed afterwards. That status only says the send was triggered, not that the mail arrived. So log the two separately: the status change in sevDesk and the delivery in the log of your mail route. Otherwise an invoice sits there marked as sent that never arrived. For an internal test print there is a separate setting that produces the document as a draft without changing the status and without triggering bookings. That is the one you use while setting things up.
So the order for any connection is: first a test draft you look at in the interface, then live operation, sending stays with a human. Resetting to draft is provided for, but only from the "open" status, and a document that has been locked down can no longer be changed at all according to the documentation. That split is the actual security architecture. Which data you hand to third parties at all, and how to handle that when AI is involved, is covered in AI and Privacy: What the AI Gets to See.
How an AI employee works on top of this
Anton, my AI employee for quotes and invoices, builds a quote PDF in my design out of an evaluated first conversation, recalculates net, VAT and gross himself, and checks the finished document before anyone sees it. Once a client says yes, he creates the contact, the quote and the invoice as a draft in the bookkeeping tool. His native tool is Lexware Office, and that is where he runs live in my own business; for other bookkeeping tools the adapter route is provided for, meaning a connection you build to the same pattern. For sevDesk that means the workflow is the same, you build the connection, and the effort for it is what level 3 above describes. Building it does not mean building it alone. You set the adapter up together with me or with people from the community, in the calls or with a question in a post.
Three rules stay fixed, and with sevDesk they pay off especially well, because the send call sits right there on the interface. He drafts, the human approves. He does not send or finalise anything unasked, but names the consequences first and wants a clear yes. And no price without a source: if two different prices for the same service sit in the material, both go on the table with their origin instead of being averaged.
What has to appear on the invoice at the end of that chain is covered in German Small Business Invoices: The Rules and German E-Invoicing: Dates and Exemptions. That is the legal position as documented there, and not tax advice for your individual case.
Frequently asked questions
Which plan includes the sevDesk API?
The Buchhaltung Pro plan. The help centre names it as the requirement, the pricing page lists the REST API among its features, and on 20 September 2026 showed a list price of 34.90 euros net per month with monthly billing, at that point with a running discount campaign. That is the state on the day it was retrieved; using the interface itself incurs no additional cost according to the help centre.
Where do I find my sevDesk API token?
Under Erweiterungen and Integrationen in the area "API-Token für Integrationen", by clicking "Einblenden", and depending on your plan also under Erweiterungen and API. To display it you have to enter your account password.
Can I connect Amazon or eBay directly to sevDesk?
Not directly. In the integration directory, Amazon and eBay run through Billbee, Etsy through Billbee or Kassenklingeln, Stripe through miraclesync. Shopify, by contrast, is listed as its own integration.
Can I limit what my tax firm sees?
The help article on tax adviser access describes real-time access to all booking-relevant data and names no restriction to individual areas. So assume the invitation releases a complete view, and only issue it to the firm you have a contract with.
Does the interface send invoices itself?
Yes, there is a dedicated call for it, and that is exactly the point to watch: it automatically marks the invoice as sent, and sevDesk notes that it may not be changed afterwards in production. The status only documents the triggered send, not the delivery, so log the two separately. Leave sending with a human.
Do I get notified when something changes in sevDesk?
The published interface description lists no webhook endpoint. That is a finding about this documentation, not about the whole product: whether there is an event notification somewhere else is a question for the vendor. For the documented route it means your application has to ask. Plan a regular, modest poll for that.
How to take it from here
Work through the three levels from the bottom up: is your case already in the account? Is it in the integration directory? Only if both answers are no are you at the API. Then settle three points first: the plan you are on, the place the token will live, and a first run that only produces drafts and sends nothing.
Which tasks you can hand off in your business at all is covered in Which Tasks You Can Hand Off to AI, and what that looks like in a one-person business is in AI for Freelancers: What Pays Off. The finished quotes-and-invoices employee, including the course and the adapter route, is in my community Claude Practitioners. If you get stuck on one of the three points, put it in a post there or bring it to the next call.
