Slovak e-invoicing 2027: what foreign-owned companies need to know
One place for every incoming invoice. Your accountant gets everything at once, you search for nothing.
Everyone must receive
From 1 January 2027 every legal entity and every taxable person in Slovakia must be able to receive e-invoices, VAT-registered or not.
VAT payers must issue
VAT payers must issue e-invoices for domestic B2B and B2G supplies.
Structured XML, not PDF
An e-invoice is structured XML (Peppol BIS Billing 3.0 / EN 16931). A PDF sent by e-mail is not an e-invoice.
Through a certified provider
Delivery goes through a certified delivery-service provider (the “digital postman”). You may have only one provider for receiving.
Archive the original XML
E-invoices must be archived for 10 years in the original XML. The provider does not do it for you.
Cross-border from 2030
Cross-border supplies follow from 1 July 2030.
Source: e-invoicing FAQ of the Financial Administration (PDF, in Slovak) · Finančná správa SR
What changes in your day
It is not another program to keep an eye on. It is the end of hunting for documents.
Documents stop being scattered everywhere.
Today invoices arrive by e-mail, from the delivery provider, from supplier portals and some still on paper. With us they have one place — and neither you nor your accountant digs for them in last month’s e-mails.
Handing over to your accountant stops hurting.
No more “send me that one from Alcon too” at the end of the month. Your accountant gets everything at once, in order, with anything missing flagged — and you don’t have to deal with it.
You see what to pay and what is already paid.
Invoices match themselves with your bank statement. You won’t pay twice, you won’t miss a due date and you won’t check it in a spreadsheet.
Nothing gets lost, even if you don’t look.
An invoice that arrives on Friday evening is waiting in its place on Monday. If it arrives twice, you’ll see it.
Indicative price
Integration from €1,500 one-off and operation from €59 per month. Exact quote after a 30-minute call — upfront, no surprises.
iOptics s.r.o. is not a VAT payer; prices are final.
"Most AI agencies send your data to the cloud and hope nothing goes wrong.
We never let it get there in the first place."
— the philosophy behind every iOptics project
The whole chain, one principle: your data stays yours.
From private AI through websites, bookings, e-invoicing and appointment reminders to infrastructure and compliance — we build and run all of it, so you get one partner instead of five vendors.
Private AI assistants with RAG
AI that knows your documents and answers with source citations. Indexing, retrieval and storage all run fully locally on your own hardware. For every question, only the query itself and 3–5 relevant chunks reach the language model — full files never leave your company. Ideal for financial advisors, lawyers, accountants and anyone working with sensitive files.
Custom web development + AI guide
Fast React/Node websites with a custom admin system, knowledge base and an AI chat that genuinely helps your customers. No bloated templates — built precisely for your business.
Infrastructure & operations
Docker stacks, Cloudflare Tunnel and WAF, our own mail server, networking (Mikrotik / Ubiquiti) and hosting. We deploy, secure and operate it — you focus on the business.
Data migration and repair
Safe migration from legacy systems — MS Access (.accdb / .mdb), outdated SQL databases or scattered Excel spreadsheets — into a modern environment (MariaDB / PostgreSQL). Along the way we clean and repair the data (duplicates, integrity, indexes, encoding) and verify that nothing is missing after migration. For businesses stuck on old software and worried about losing their data.
GDPR & compliance
Complete documentation — DPA, technical and organizational measures (TOM), DPIA and a sub-processor list — prepared for the Slovak regulatory context (NBS, ÚOOÚ). Included with every AI deployment.
Security & hardening
WAF rules, closing off public endpoints, encryption at rest (FileVault), redundant backups (RAID), access audits. Security as the standard, not an add-on.
Bookings, appointments & reminders
An online booking system with automatic SMS and email appointment reminders — customers get a heads-up a day ahead, you get fewer no-shows. Plus bulk announcements to customers: changed opening hours, promotions, holidays. Ideal for dental and optical practices, clinics and any business that takes bookings. Connected to your calendar, data stays with you.
E-invoicing (Peppol / EN 16931)
From 1 Jan 2027, VAT payers must be able to both issue and receive e-invoices (Peppol BIS / EN 16931) — and every business will need to be able to receive them. Standard accounting software has this covered. But what if you run a custom system, a legacy database, an e-shop, or specialized software that's on none of the supported-software lists? That's exactly where we come in: we connect anything to a certified access point — invoices are sent and received automatically, and structured data flows straight into your system, no re-typing, no errors from PDFs. We'll get you ready in time, already in the voluntary 2026 phase. Bonus: clean structured data also improves your AI/RAG. Try the demo below →
Data is indexed on your premises. Only the question reaches the cloud.
This is the difference between "we'll send everything to OpenAI" and a solution that holds up in front of a regulator. Full documents stay physically on your server.
Documents stay local
Files, contracts and databases are stored and indexed on your own hardware. Encrypted at rest, backed up with RAID redundancy.
Retrieval runs locally
Embeddings (bge-m3) and a vector database (Qdrant) find the relevant chunks without any internet connection.
Only the query + chunks go out
The AI model only ever receives the question and 3–5 retrieved chunks — typically a few sentences, never the whole file.
Answer with citations
You get an answer that points to the exact source. No ports open into your network — everything runs over an encrypted tunnel.
Ask away. This is exactly the AI you'll get.
The real iOptics AI assistant. Ask about services, pricing, GDPR or how deployment works. We can fill this same interface with your own documents.
This chat answers questions about iOptics. Below, try the same RAG on your own document ↓
Upload a document. Ask it a question. Watch it work.
This isn't a video or a screenshot — it's the exact same RAG we deploy for clients. Upload a PDF, DOCX or TXT and ask it questions. The document is processed in memory on our server, indexed locally (bge-m3), and automatically deleted after 30 minutes — nothing is ever written to disk.
Drop a document here or click
Processed in memory · deleted after 30 min · nothing is stored
Runs on our server: local bge-m3 embeddings · only the query + retrieved chunks reach Claude · answers with source citations.
PDF won't cut it a year from now. Upload an e-invoice and watch it read itself.
From 1 Jan 2027, Slovakia's mandatory B2B e-invoicing (Peppol BIS / EN 16931) applies to VAT payers, and every business will need to be able to receive it. Unlike a PDF, where data has to be pulled out via OCR and AI (slow, error-prone), an e-invoice is structured XML — it's read accurately and instantly. Upload your own e-invoice (XML), or click "Try a sample invoice" and we'll show it on a prepared example. Tip: upload a PDF invoice too and compare — you'll see why it won't be enough after 2027.
Drop an e-invoice (XML) or PDF here
Processed in memory · nothing is stored
The same parser feeds our clients' accounting systems: e-invoice in → precise data out, no re-keying, no AI guesswork. Sending/receiving via a certified access point.
Real deployments, running in real operations.
From the regulated financial sector to local businesses — solutions running in production every day.
AI assistant for an independent financial advisor
A private RAG assistant over contracts and client files for a financial advisor regulated by the NBS. Fully local indexing, complete DPA + TOM + DPIA package.
Clinic portal with online booking
A patient portal, a virtual receptionist "Sabina" (AI chat), online bookings and automatic SMS/email appointment reminders. Secured API via Cloudflare Tunnel and WAF, hardened database holding thousands of records.
Website + AI guide for local businesses
Modern React websites for a butcher shop and a café, with content management, bookings and an AI chat that helps customers. Deployed on our own infrastructure.
From the first call to production — no surprises.
Consultation
We map out what data you have, what you're solving and what regulatory requirements apply. No commitment.
Proposal & quote
Architecture, scope and a transparent quote — both the one-off build and the monthly operations.
Deployment
We build, secure and test directly in your infrastructure, including GDPR documentation.
Operations
Monitoring, updates and support. One partner instead of five vendors.
Indicative packages. Final quote depends on scope.
Every project is different — the items below are starting points, not a price list. You'll get an exact quote after a consultation.
Website + AI guide
- Custom React/Node website
- AI chat guide for your customers
- Online booking + SMS/email appointment reminders
- Admin system + knowledge base
- SEO foundation, deployment, HTTPS
iOptics s.r.o. · not VAT-registered · pricing is indicative and finalized upon consultation