OVM
Public authority
Box of a public authority, ministry, municipal district. Official communication is delivered here — no refusal possible. 4notify monitors incoming ISDS messages and instantly informs the legal team per the internal rotation.
Datová schránka in practice: ISDS API, callbacks and archival for developers
Datová schránka (ISDS) is the Czech flagship electronic delivery system — mandatory for OVM since 2009 and for most legal entities since 2023. While email is fast, ISDS carries legal-delivery weight with a 10-day delivery fiction, an immutable audit trail and 10-year archival. 4notify doesn't replace ISDS — it complements it: SMS/email notifications alert you that an ISDS message arrived, or conversely that a document was sent and statutory deadlines have begun.
Three box types, three behaviours
PFO
Self-employed individual
Self-employed box. Optional pre-2023, mandatory from 2023 for every self-employed person (Act 261/2021). For accounting pipelines ISDS is the source of incoming notices from the tax office — 4notify converts the message into SMS „new tax notice, ABC123“.
PO
Legal entity
Box of a commercial company, NGO, cooperative. Mandatory since 2023 for most legal entities registered in the Commercial Register. 4notify maintains DS_ID ⇄ Business ID mapping from base registers, so manual lookups disappear.
ISDS message flow — 4 phases
- 01
Look up the data box ID
From a Business ID, self-employed name or OVM name we query base registers (ROS/RPP) via the ISDS FindDataBox API. Cached for 7 days. Without this step a message can't be addressed.
- 02
Send the data message
ISDS CreateMessage method accepts a MIME-like body with attachments (PDF/A is required for official documents). 4notify ensures attachments respect the 20 MB limit and carry the correct metadata names.
- 03
Delivery receipt and delivery fiction
On delivery we get a „dodejka“ (message stored) and on recipient login a „doručenka“ (message opened). If the recipient doesn't log in within 10 days, delivery fiction kicks in (§ 17 of Act 300/2008) — 4notify SMSes you „statutory deadlines run from today“.
- 04
Archival and vault download
After 90 days ISDS deletes the message from the live queue. 4notify downloads every message within that window into an S3-compatible vault with SHA-256 checksum and retains for at least 10 years — matching the statutory accounting retention.
Frequently asked
Is 4notify an official Datová schránka client?
We are not an official client. 4notify uses the publicly published ISDS API (authentication via system certificate or credentials) and adds a monitoring, notification and archival layer on top. The Ministry of the Interior and Czech Post remain the ISDS operators.
Can we use email instead of ISDS?
For official communication with public authorities, usually no — the law requires the data box if one is established (§ 17 of Act 300/2008). 4notify handles both channels in parallel: ISDS for the official document, email for civilian counterparties.
How do you handle legal-team rotation when a message arrives?
4notify supports „inbox routing“: by subject, sender or attachment a message triggers a Slack notification into a specific channel (#tax, #legal, #ceo). After 4 hours without reply it escalates to the on-call rotation.
What about archival beyond 10 years?
The archive layer supports a „retain forever“ policy or auto-delete after a configured window; metadata remains in the audit trail even after the original is purged. Consult your tax advisor per document type.
Can we call ISDS from our own app, bypassing 4notify?
Yes, the ISDS API is public. 4notify makes sense when you want a notification layer (SMS, email, Slack), a structured audit, an archive vault and a bidirectional workflow without writing your own orchestrator.
Bridge ISDS to your email, SMS and Slack
Start the 14-day free trial. No card needed — just a Business ID and the contact of the person responsible for the data box.