CZ OSS VAT Return (OSSEI1, Union scheme)

The Czech One-Stop-Shop return for the Union scheme as the EPO form OSSEI1, validated against the official schema.

Version	19.0.1.0.0
Edition	Community and Enterprise
Licence	AGPL-3
Requires	`l10n_cssk_oss_base`, `l10n_cz`

What it is for

A Czech VAT payer or identified person registered for the One-Stop-Shop Union scheme (zvláštní režim jednoho správního místa — režim Evropské unie) files a quarterly return of the VAT charged on distance sales and on services to consumers in other EU states. This module turns the return computed by l10n_cssk_oss_base into the EPO form OSSEI1 (DAP OSS — režim EU — Přiznání k DPH) and checks it against the official schema before it is attached.

Everything about preparing the return — the rows, corrections, exchange rates and the export steps — is described in the shared guide. This page covers what is Czech.

Legal background

All references are to the VAT Act, No. 235/2004 Sb.; statutory terms are given in Czech.

Who may use the scheme. Under § 110l odst. 1 a person established in Czechia (or, without an EU establishment, dispatching goods from here) who is a plátce or identifikovaná osoba and does not use the Union scheme in another member state. Registration is applied for under § 110p.
One tax office for everyone. The special scheme is administered by the Finanční úřad pro Jihomoravský kraj (§ 110a odst. 3), not by the company's own office. The form therefore carries no tax-office code.
Electronic filing only. Form filings in the special scheme, except the registration, are made electronically through the electronic portal (§ 110o odst. 1).
Period and deadline. The tax period is the calendar quarter (§ 110zb); the return is due by the end of the following month, also when nothing was supplied, and the deadline does not move to the next working day (§ 110zc).
Amounts. Tax is stated in euro to two decimal places bez zaokrouhlování (without rounding); conversion uses the ECB rate for the last day of the period or the next day of publication, and for a correction the rate used for the original supply (§ 110ze).
Corrections. A correction is part of the return for the period in which the payer learned of the facts, and cannot be made after three years from the deadline of the original return (§ 110zd).

The form

The module produces one form, OSSEI1, structure version 01.01.04 of 13 December 2021, valid for every quarter from Q3 2021. That is the Czech way of versioning: EPO publishes a single schema, ossei1_epo2.xsd, and replaces it in place, and a return for an old quarter is filed in the structure current at the time of filing. There is therefore one open-ended form version, DAP OSS — režim EU (OSSEI1), and nothing is chosen by year.

Neither the schema nor the structure version in the file (verzePis) can show that it is out of date — a stale schema validates a stale file perfectly. The module pins the schema by size and checksum, and a test fails if the bundled schema does not match. When Finanční správa publishes a new structure, the module must be updated.

What the file contains:

Part	Content
`VetaD`	quarter, year, DIČ without the `CZ` prefix, company name, `A` for a return with data or `N` for a nil return, and the start or end date when the registration began or ended during the quarter
`VetaP`	DIČ
`VetaR`	one per member state of consumption × rate × goods (`G`) or services (`S`): the state supplied from, rate type `Z` (standard) or `S` (reduced), rate, taxable amount and VAT in euro; Greece as `EL`
`VetaO`	one per corrected quarter and member state: the correction of VAT in euro, with its sign

Setting it up

The company's Tax ID must be a Czech DIČ: CZ followed by 8 to 10 digits. The export refuses anything else before EPO would.
The form version is installed with the module. Choose DAP OSS — režim EU (OSSEI1) on each return.
Set up Odoo's OSS taxes as the shared guide describes.

Filing

Prepare and compute the return under Účetnictví → Výkazy → Zákonné výkazy → Přiznání k DPH OSS and confirm the ECB rates.
Exportovat XML (Export XML). The file is validated against OSSEI1 and attached.
File it through the Finanční správa electronic portal (EPO) — by loading the file there, or by sending it from Odoo with l10n_cz_epo through Podat (File it).
Označit jako podané (Mark Submitted) to keep the filed copy.

Pay the tax in euro, by bank transfer to the tax office's euro account, quoting the reference number of the return (§ 110h). The module does not create the payment.

Limitations

Rounding. § 110ze odst. 1 asks for euro amounts to two decimals without rounding. The module rounds the VAT of each row half-up to cents, so a row can differ by one cent from a truncated figure. Check this with your tax adviser before filing.
Only the Union scheme (OSSEI1). The non-Union scheme (OSSNI1), the import scheme (OSSII1) and the MOSS return for quarters before Q3 2021 (OSSDI1) are not built.
A correction that has to be filed with the member state of consumption directly, after the three-year period, is not prepared here.
A new EPO structure needs a module update; there is no warning other than EPO rejecting the file.
The checks are those described in the shared guide; EPO's own content checks run only when the file is submitted or checked there.