Schedule

Which dates and deadlines apply to issuing and sending e-invoice?

Short answer

The key dates are 2026 as the voluntary preparatory period, 1 January 2027 as the start of mandatory e-invoicing for the specified domestic supplies, and 1 July 2030 as the planned next phase of wider digital reporting. The deadline for issuing a particular invoice is determined by the VAT Act, not by the use of XML. The operational process must also track validation, dispatch, delivery and any errors.

2026

Voluntary mode

Testing systems, postman, XML and accounting.

1. 1. 2027

Mandatory B2B/B2G core

Beginning of the mandatory regime according to Section 85o.

Time limit

According to the VAT Act

The specific type of delivery and invoice must be tracked.

1/7/2030

Next phase

Planned follow-up to broader digital reporting.

Detailed explanation

In practice, four time frames overlap: the effective date of the mandatory regime, the date of delivery or receipt of payment, the deadline for issuing the invoice, and the technical time of delivery via the postal service. A company must have a process in place that can manage all four. It is not sufficient to simply store an invoice in the ERP system if it has not passed validation or has not been sent. Similarly, it is not enough to send an incorrect document if it is returned as technically rejected.

As set out in the law and technical rules

The obligation to use e-invoicing arises from Act No. 385/2025 Coll. and from Sections 76a and 85o of the VAT Act. The deadlines for issuing invoices arise from the general invoicing provisions of Section 71 et seq. of the VAT Act.

Practical examples

The company is testing XML export and participant lookup in June 2026 without any impact on live reports.
The supply in January 2027 complies with Section 85o; the invoice will be issued and sent as an e-invoice within the statutory deadline.
A technical error on the last day of the deadline must be resolved immediately, as a failed transmission does not constitute secure delivery.

Common misconceptions

“The date 1 January 2027 supersedes all previous deadlines.” No. It is the electronic invoicing regime that is changing, not the basic principle of deadlines.
“Sending and delivery are the same thing.” No. You must monitor the delivery status and any errors.
“There’s no need to worry about 2026.” Without testing, errors will occur in live operation.

Conclusion

Manage the statutory issue date and deadline together with validation, dispatch, delivery and evidence of the document’s status.

Legal and technical basis

Act No. 385/2025 Coll.
Act No. 222/2004 Coll. on VAT, Section 71 et seq.
Act No. 222/2004 Coll. on VAT, Section 76a
Act No. 222/2004 Coll. on VAT, Section 85o
VAT in the Digital Age

Official cases from the Slovak Financial Administration’s FAQs

The following questions and answers are taken from the current July FAQ from the Financial Administration and have been assigned to this topic. Grouping the cases prevents the creation of duplicate pages, whilst retaining the full answer and the exact wording of the question.

Example No. 17: What are the key deadlines for the roll-out of electronic invoicing in Slovakia?

The roll-out of electronic invoicing in Slovakia is being implemented through a phased approach, with mandatory deadlines spread across the years 2026–2030, featuring key milestones for different types of transactions and reporting requirements. Current and upcoming deadlines: • The transition period in Slovakia will run from 1 January 2026 to 1 January 2027. • The obligation to invoice B2B and B2G transactions in Slovakia will come into force on 1 January 2027. • International electronic invoicing is planned from 2030.

Primary source: Financial Administration of the Slovak Republic, FAQ 9/VAT/2025/IM k e-invoice, July 2026 update. Processed and checked on 13 July 2026.