E-invoicing CTC models: clearance, reporting and interchange
Continuous transaction controls (CTC) are rules that give a tax authority invoice data at, or shortly after, the moment of each sale, instead of in a periodic return. The main models are clearance (the authority, or a provider it authorises, must approve or deliver the invoice before it is valid), real-time reporting (the invoice moves freely and its data follow), and decentralised exchange networks such as Peppol, to which some authorities add themselves as a "fifth corner".
There is no binding legal taxonomy of CTC models. As at 2026-10-07, neither the OECD FTA report, Directive (EU) 2025/516 nor OpenPeppol's reference documents define the categories as legal terms, and each country's law uses its own vocabulary. The closest official reference is the OECD Forum on Tax Administration's report Tax Administration 3.0 and Electronic Invoicing: Initial Findings (28 September 2022). It states that "There are several architectural models that can describe the way businesses, tax administrations and intermediary service providers collaborate", and names two elements that separate them (printed p. 30):
- Whether invoices are cleared. "In a clearance model, the supplier is required to either obtain an authorisation from the tax authority as a pre-condition to send the invoice, or send the draft e-invoice to the tax authority, which in turns delivers the e-invoice to the customer." In a no-clearance system the supplier sends the e-invoice straight to the customer, without asking the authority for approval.
- Whether a central IT platform receives the documents. That recipient can be "the tax administration itself or private businesses authorised by the tax administration to act on its behalf".
Source snapshot captured 2026-10-07 — original
The labels themselves come from two other bodies, and the OECD report reproduces both:
- The European Commission's 2022 classification of digital reporting requirements (DRR). OECD Box 1.2 (printed p. 16) groups them into two periodic forms (VAT listings and SAF-T) and two continuous forms: real-time reporting, defined as transmitting transaction data "shortly after issuance of the invoice" where "the invoice itself does not need be transmitted to the tax authority", and e-invoicing with or without clearance. The source is the Commission's VAT in the digital age: final report, Volume 1 (doi 10.2778/541384).
- OpenPeppol's four CTC models. OpenPeppol, the non-profit association that owns the Peppol framework, analysed "CTC implementations in over 60 countries" and grouped them into an interoperability model, a real-time invoice reporting model, a centralised exchange model and a clearance model (Peppol CTC Reference Document v1.0, September 2021, §3.2). The same Reference Document describes the "5-corner" model, and OpenPeppol's Addendum (September 2023) bases Peppol CTC on "Decentralised Continuous Transaction Controls and Exchange". The UAE Ministry of Finance uses the acronym "DCTCE" for its model, and Singapore's IRAS describes a "5th corner to the 4-corner model". At least two tax authorities have adopted this terminology in their own documents, as at 2026-10-07 (see below). OpenPeppol is a framework owner, not a tax authority, so its labels describe architectures, not anyone's legal obligation.
How it works
The OECD report reproduces OpenPeppol's overview diagram as Figure 3.2, "Examples of different invoice data exchange CTC models". It shows interoperability as the "Foundation for CTC" and three "Existing CTC models": real-time reporting, centralised invoicing and clearance. A note under the figure records that OpenPeppol recommends "a decentralised preclearance/ real-time reporting model with regulated exchange" for Peppol.
Source snapshot captured 2026-10-07 — original
The practical question for a business is always the same: is my invoice legally valid before the tax authority (or its delegate) has seen it? If not, the system is a clearance system. If yes, and the authority only receives data, it is a reporting system.
Clearance — centralised
The authority's own platform sits in the middle of every invoice. It checks the document and either delivers it to the buyer or stamps it with an identifier that makes it valid.
- Italy (SdI). The Sistema di Interscambio, run by the Agenzia delle Entrate, receives FatturaPA files, checks them and forwards them to public bodies or to private B2B and B2C customers (fatturapa.gov.it). The obligation applies to invoices issued from 1 January 2019 (art. 1(916), Law 205/2017). An e-invoice sent straight to the customer's certified mailbox (PEC) without passing through SdI "si ha per non emessa", meaning it is treated as never issued (Agenzia delle Entrate consolidated FAQ, n. 44). An invoice that SdI rejects is also treated as not issued (Circolare 14/E of 17 June 2019).
Source snapshot captured 2026-10-07 — original
- Poland (KSeF). Under Article 106na of the VAT Act, a structured invoice is deemed issued on the day it is sent to the Krajowy System e-Faktur, and deemed received on the day KSeF assigns it an identifying number (consolidated VAT Act, checked 2026-10-07). The obligation started on 1 February 2026 for taxpayers whose 2024 sales including VAT exceeded PLN 200,000,000, and on 1 April 2026 for the rest (transitional rules in Arts 145l and 145m).
Source snapshot captured 2026-08-31 — original
- Saudi Arabia (FATOORA). One system runs two models. In Phase 2 ("Integration"), applied in waves since 1 January 2023, each standard tax invoice (B2B and B2G) "must be cleared by the Authority as a prerequisite for sharing them with the buyers and for such Electronic Invoice to be regarded as legal and valid". Simplified tax invoices (mostly B2C) are not cleared: they are reported to FATOORA within 24 hours of issuance (ZATCA Detailed Guidelines for E-Invoicing, v2, §6.4 and §2.15; roll-out phases, checked 2026-10-07).
Source snapshot captured 2026-10-07 — original
Clearance — through authorised providers
Some clearance systems delegate the checking to private, state-authorised providers. OpenPeppol calls this decentralised clearance, and also separates pre-clearance ("hard" clearance, before the invoice is exchanged) from post-clearance ("soft" clearance, shortly after) (Peppol CTC Reference Document, p. 14).
- Mexico (CFDI) appears in OpenPeppol's 2021 Reference Document as a pre-clearance example: the electronic invoice (CFDI) must be certified before it is valid, through providers that the tax administration (SAT) authorises. The current CFDI standard, version 4.0, has been mandatory since 1 April 2023 (SAT).
Source snapshot captured 2026-09-23 — original
- Malaysia (MyInvois) works in a clearance style. The supplier submits each e-invoice to the Inland Revenue Board (IRBM) for validation "immediately". Validation happens "in near real-time", and the validated invoice receives an IRBM Unique Identifier Number, a validation timestamp and a validation link. The buyer can request rejection within 72 hours of validation. Implementation is phased by taxpayer group from 1 August 2024 (Table 1.1) (IRBM e-Invoice Guideline v4.8, §2.3, checked 2026-10-07). The IRBM Unique Identifier Number is assigned on validation:
Source snapshot captured 2026-10-07 — original
Real-time and near-real-time reporting
The invoice is exchanged between the parties as before, in any lawful form, and its data go to the authority within a short time limit. No approval step comes first.
- Hungary (Online Számla). Data on issued invoices reach the tax authority (NAV) in real time. Reporting began on 1 July 2018 for invoices to domestic VAT payers with at least HUF 100,000 of VAT, extended to all domestic B2B invoices on 1 July 2020, and since 4 January 2021 covers every invoice under the VAT Act's invoicing rules, including invoices to non-VAT-payers and foreign buyers (NAV Online Számla user manual, §3.1, checked 2026-10-07).
Source snapshot captured 2026-09-30 — original
- Spain (SII). The Suministro Inmediato de Información keeps a business's VAT ledgers on the Agencia Tributaria's e-office through the "suministro cuasi inmediato de los registros de facturación". The AEAT says plainly "no se trata de remitir las facturas concretas" (it is not about sending the actual invoices): records are sent, not invoices (AEAT, checked 2026-10-07). It is mandatory for monthly VAT filers, including large businesses with turnover above EUR 6 million and REDEME registrants, and optional for others. Spain's planned B2B e-invoicing (Royal Decree 238/2026) and Veri*factu are separate layers on top of SII. SII records are due within four days, excluding Saturdays, Sundays and national holidays.
Source snapshot captured 2026-08-19 — original
- Greece (myDATA) began as electronic transmission of invoice data to AADE under Article 15A of the Tax Procedure Code (Joint Decision A.1138/2020). It is now becoming provider-based e-invoicing. Decision A.1197/2026 (ΦΕΚ Β΄ 5905/30.09.2026) moved phase 2 to 2 November 2026, with a transition period from 2 November 2026 to 31 January 2027 (Diavgeia). Phase 1 of mandatory B2B e-invoicing started on 2 March 2026 under Joint Decision A.1044/2026 (Diavgeia).
Source snapshot captured 2026-09-30 — original
Decentralised CTC: the 5-corner model
Here the invoice travels between the two businesses' accredited providers, as on an interoperability network, and the providers also send the tax data to the authority as part of the same process. OpenPeppol describes its version as "a decentralised CTC model with regulated document exchange": the supplier's provider (corner 2) validates the invoice, reports the full document or a Tax Data Document (TDD) to the corner the tax authority designates (corner 5), and delivers the invoice to the buyer's provider (corner 3), which validates it and reports too (Peppol CTC Reference Document, p. 18).
- United Arab Emirates. The Ministry of Finance calls its model "Decentralized Continuous Transaction Control and Exchange - DCTCE". The supplier (corner 1) submits invoice data in the PINT AE format to its Accredited Service Provider (corner 2). Corner 2 transmits the e-invoice to the buyer's provider (corner 3) and, in parallel, reports the Tax Data Document to corner 5 (MoF eInvoicing hub, checked 2026-10-07). The MoF's Electronic Invoicing Guidelines V1.1 (1 June 2026) define the "5 Corner model" with the Federal Tax Authority as corner 5. Businesses with revenue of AED 50,000,000 or more must appoint a provider by 30 October 2026 and go live on 1 January 2027 (Ministerial Decision No. 244 of 2025, Art. 5(1)(a), as amended by Ministerial Decision No. 66 of 2026; consolidated text). Corner 5 receives the Tax Data Document:
Source snapshot captured 2026-10-07 — original
- Singapore (InvoiceNow). InvoiceNow is Singapore's Peppol-based network. Under the GST InvoiceNow Requirement, IRAS connects to it via the Access Point to receive copies of invoice data, "through the introduction of a 5th corner to the 4-corner model". For Peppol invoices, the copy reaches IRAS "on a real-time / near real-time basis" once the invoice reaches the customer's Access Point (IRAS e-Tax Guide, 2nd edition, 9 March 2026, paras 5.3 and 8.1). The requirement started on 1 November 2025 for newly incorporated companies that register voluntarily for GST, and on 1 April 2026 for all new voluntary registrants (para 2.3(a)). IRAS describes its role as a 5th corner:
Source snapshot captured 2026-10-07 — original
- France is decentralised but platform-based rather than Peppol-based. Invoices between French businesses must pass "par l'intermédiaire d'un tiers, appelé plateforme agréée" (a private company registered by the State), and the platform sends the data to the administration. Since Décret 2026-677 the public platform is no longer an exchange channel; it keeps the central directory and the data transmission to the administration. Supplier and buyer may use different platforms. Transactions outside the e-invoice flow (B2C, cross-border) and certain payment data are covered by e-reporting (impots.gouv.fr, checked 2026-10-07). E-invoicing and e-reporting follow the same calendar.