Documentation · Digital assets

DAC8.

Preparing, validating and submitting crypto-asset user and transaction data under the EU crypto-asset reporting framework.

Manual Tax Reporting Engine → DAC8 · Version 1.0
Before you beginThis guide starts at the module. Accounts, navigation, Settings and how sessions work are covered once in the Getting Started guide.

What this module does

DAC8 is the EU implementation of the OECD Crypto-Asset Reporting Framework. Reporting crypto-asset service providers identify their reportable users, and the relevant transactions those users carried out, and report them annually to their local tax authority, which exchanges the information with other member states.

The module is the same engine as DAC2 and CRS. What changes is the data you load — crypto-asset users and transactions rather than financial accounts — and the schema applied on export.

The REGREP DAC8 module takes your user and transaction data as a spreadsheet, checks it against the structural and regulatory rules, tells you what is wrong with it, and produces the DAC8 XML package for submission. It works in three stages, shown as three cards on one screen: data input, regulatory validation, and conversion to the submission format.

DAC8 or CARF?

The two cover the same crypto-asset data through the same engine. DAC8 is the EU implementation and files to an EU member state authority; CARF covers the jurisdictions outside it. Which one applies is determined by the jurisdiction on your corporate profile.

Before you start

Important

Complete Settings → Corporate Information before creating a DAC8 session. The reporting institution’s identity is written into the package directly from these fields, and an incomplete profile produces a package your tax authority will reject.

The fields DAC8 requires are:

FieldWhy DAC8 needs it
Legal Entity NameIdentifies the reporting institution in the XML.
LEI NumberThe 20-character Legal Entity Identifier. Check that the field validates — an invalid LEI is carried into the export.
Type of EntityThe entity classification for reporting purposes.
Country of IncorporationDetermines the transmitting jurisdiction.
Company TypeThe business entity structure.
Tax Identification Number (TIN)The reporting institution’s own TIN.
GIINThe Global Intermediary Identification Number.
FATCA FilerThe filer status or code.

Save the tab before leaving Settings.

Opening the module

Solutions → Regulatory Reporting → Tax Reporting Engine → DAC8.

NoteIf DAC8 appears greyed out, the module is not enabled for your firm. Contact your REGREP account manager. The other tax frameworks are separate modules with their own entitlements and their own guides.

Sessions

A DAC8 session is one submission: a reporting year, a submission type, and the data that goes with it. Corrections to a submission you have already filed are handled as separate, linked sessions rather than by editing the original.

The list shows, for each session, its name, reporting year, report type, version, the parent session where one applies, the submission type, and when it was created and last opened. Two row actions are available: open the session, and delete it.

Warning — this cannot be undone

Deleting a DAC8 session removes it and its uploaded data permanently, and there is no archive tab in this module to fall back on. If the session produced a package that has been filed, keep it — it is your record of what was submitted, and a later correction session needs it as its parent.

Creating a new submission

Use this for the first submission covering a given reporting year. Select + on the session list.

FieldWhat to enter
Session NameA descriptive name. Including the year and the words “original” or “correction” makes the list readable later.
Session YearThe tax reporting year the data covers — not the year you are submitting in.
Submission TypeOpen the Submission Type list and choose the new-submission entry for DAC8.
VersionFixed at 1 for an original submission.

Select SAVE. You are taken to the file upload screen.

Correcting a submission you have already filed

If an error or omission is found in a submission that has already gone to your tax authority, do not edit the original session. Create a correction session linked to it. The link preserves the audit trail and tells the receiving authority which report is being corrected.

FieldWhat to enter
Session NameSomething that identifies what is being corrected — for example “DAC8 2025 — Correction of TIN errors”.
Session YearThe same reporting year as the parent session.
Submission TypeThe correction entry in the Submission Type list.
Dependent / Parent SessionThe original session in which the error occurred. Selecting it links the two.
VersionIncrements automatically — 2 for the first correction, 3 for the next, and so on.
NoteA correction session carries only the records being corrected, not the whole original file. Check your tax authority’s guidance on whether corrected, deleted or added records are expected, and prepare the upload file accordingly.

Uploading your data

A newly created session opens on the upload screen. Drag a file onto the upload area, or select it to browse. Accepted format: .xlsx.

The sidebar on the left shows the session’s parameters — jurisdiction, creation timestamp, reporting year, submission type and version — so you can confirm you are loading data into the right session before you upload. Once the file is attached, REGREP begins processing immediately and the screen changes to the three processing cards.

Processing and validation

The three cards run in order. Each has to be satisfied before the next is meaningful: Data Input reports what was read from your file, Regulatory Validations reports what passes the DAC8 rules, and XML Conversion builds the submission package.

Data Input

This card confirms the file was structurally readable and reports what it contained. A progress indicator runs during ingestion and is replaced by “Structural Validation Successful” when the file has been read.

CountWhat it means
TotalAll rows processed from the file.
UsersReportable crypto-asset users identified.
PartiesUsers and controlling persons.
UndocumentedUsers with insufficient documentation to establish tax residence.
TINsTax identification numbers detected across all parties.
Important

Check these counts against your own source system before going further. If the count is materially different from what you expect, the file is wrong or has been truncated — reconciling now is far cheaper than discovering it after submission.

UPLOAD NEW replaces the file with a revised one and re-runs the whole process.

Regulatory Validations

This card checks the ingested records against the DAC8 reporting rules — formatting, structure and logical consistency.

FigureWhat it means
Valid RecordsRows that pass every regulatory check.
ErrorsRows that fail at least one check. These will not be included in a compliant package.
TINs IdentifiedThe total number of tax identification numbers found.
Valid TINsHow many of those pass format validation for the jurisdiction they claim.

Select DOWNLOAD ERRORS to export the error log. It lists each failing record and the reason it failed. Correct the records in your source data, return to the Data Input card and select UPLOAD NEW with the corrected file. Repeat until the error count is zero, or until every remaining error is one you have consciously accepted.

Important

The error log contains the failing records themselves, which means it contains names and tax identification numbers. Treat the downloaded file as personal data.

NoteA TIN that fails validation is not always an error in your data. Some jurisdictions do not issue TINs to individuals, and some issue them in formats that change over time. Where a TIN is genuinely unavailable, follow your tax authority’s guidance on the permitted placeholder rather than inventing one. The TIN Validation module can check individual numbers or a batch outside a reporting session.

XML Conversion

The third card builds the submission package. The gauge shows conversion progress. Where the receiving authority expects one file per reportable jurisdiction, a Countries filter lets you produce a package for a single jurisdiction or for all of them at once; where it expects a single consolidated package, the filter is not shown.

DownloadUse it for
DOWNLOAD XMLThe DAC8 XML package. This is the file you submit.
DOWNLOAD JSONThe same data in a structured format, for API integration or internal record-keeping.
DOWNLOAD EXCELA readable summary workbook of the validated data, for internal review and sign-off.
Important

Before you submit, open the XML and confirm the reporting institution block carries the correct legal entity name, LEI, TIN and GIIN. These come from Settings, and an error there is invisible in the counts on screen but fatal at your tax authority.

A complete submission

  1. Confirm Settings → Corporate Information is complete and saved, and that the LEI field validates.

  2. Create the session: name, reporting year, the DAC8 new-submission type, version 1.

  3. Upload the user and transaction data file (.xlsx).

  4. Check the Data Input counts against your source system.

  5. Review the Regulatory Validations card. Download the error log if there are errors.

  6. Correct the source data and re-upload. Repeat until you are satisfied with the error count.

  7. Have the submission reviewed by someone other than the preparer, using the Excel download.

  8. Download the XML package and check the reporting institution details inside it.

  9. Submit to your local tax authority through their own portal.

  10. Record the submission reference against the session, and retain the session — a later correction will need it as its parent.

NoteREGREP produces the submission file; it does not transmit it. Filing is done through the receiving authority’s own portal.

Handling personal data

DAC8 files are unlike most of the data you load into REGREP. They contain named individuals, their addresses, their tax residences and their tax identification numbers, together with financial information about them. That is personal data under the GDPR.

  • Upload only the data needed for the reporting obligation. Do not load a fuller extract because it was easier to produce.
  • Treat the downloaded error log and the Excel summary the same way you treat the source file. They contain the same personal data, and they are the copies most likely to end up on a desktop or in an email.
  • Keep downloaded packages in the location your firm has designated for regulated records, not in a personal downloads folder.
  • Delete local working copies once the submission is filed and your retention copy is in place.
  • Restrict access to the DAC8 module to the people who need it. Access is controlled through Team Management.

Troubleshooting

SymptomLikely cause and fix
DAC8 is greyed out in the menuThe module is not enabled for your firm. Contact your REGREP account manager.
The upload is rejectedThe file is not .xlsx, or its structure does not match what the module expects. Check the format before re-uploading.
The counts do not match my source systemThe file is wrong or truncated. Reconcile before going further — the engine will happily validate an incomplete file.
Valid TINs is lower than TINs IdentifiedSome numbers fail format validation for the jurisdiction claimed. Use the TIN Validation module to check them individually.
The Countries filter is missingExpected behaviour where the authority wants one consolidated package. Otherwise, check the country of incorporation in Settings.
The package is rejected after filingMost often the reporting institution block. Re-check the legal entity name, LEI, TIN and GIIN in Corporate Information, then produce a correction session.

Document control

VersionDateChange
1.0January 2026First issue. Documents the shared Tax Reporting Engine workflow as it applies to DAC8. Screenshots and the numeric submission-type codes are pending.

REGREP is an independent software provider. This manual describes how to operate the platform and is not legal, tax or regulatory advice. Confirm scope, thresholds and submission dates with your competent authority before you file.

Other guides

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