How ERPNext DATEV integration hands your books to your tax consultant
A German company running ERPNext whose tax consultant works in DATEV needs a reliable way to hand over its books. The DATEV Integration app, published by ALYF GmbH on the Frappe Cloud Marketplace, covers three outputs: submitted vouchers emailed to DATEV Unternehmen Online, General Ledger entries exported in DATEV CSV format, and a ZIP file containing the DATEV report with master data for the consultant's DATEV system. This is an export and handover method, not a live two-way sync, so changes made in DATEV do not flow back into ERPNext. DeployOpen implements and configures the handover around your books, but it does not prepare, issue or attest tax filings. That responsibility stays with you and your consultant.
Before you rely on the app, agree with your consultant which outputs they need, how often, and in what order. Vouchers sent by email depend on the consultant's DATEV Unternehmen Online setup and the address they provide, so confirm that address and test one voucher end to end. The General Ledger export depends on your chart of accounts and account numbering matching what the consultant expects, so check account codes, cost centers and the fiscal year window before the first full export. The master data ZIP must match the customer and supplier records the consultant already holds, so decide who owns master data changes during the period. Confirm the current app version, its supported ERPNext version and any Frappe Cloud requirements with ALYF GmbH and the ERPNext DATEV integration documentation before you plan the rollout.
What you need before the DATEV export can run
The DATEV Integration app depends on a correctly configured ERPNext site, not only on the app itself. The six items below cover the software baseline, the books, the mail route and the agreement with your tax consultant, and each one changes what the export produces.
Supported ERPNext version and hosting
Start by confirming which ERPNext major version the DATEV Integration app supports, with ALYF GmbH and in the app documentation, since exact compatibility is not settled here. Version 14 reached end of life on January 31, 2026, so a new build should not start there. ERPNext can run on Frappe Cloud, with Docker Compose or manually with bench. Pick the hosting model before configuration, because the app is listed on the Frappe Cloud Marketplace and that route differs from a self-hosted install in your own infrastructure.
German chart of accounts
Your ledger must use the chart of accounts your tax consultant maps to DATEV, with account numbers that match that frame exactly. Ask the consultant which standard chart applies and whether they supply the account list. Check that every account used in sales, purchasing, payroll and bank postings has a number, a root type and a tax mapping. Accounts created ad hoc during go-live are the most common cause of unmapped lines in a General Ledger export, so freeze the chart before the first live voucher is submitted.
Company and fiscal year setup
Create one ERPNext company per legal entity that the consultant will book, and set the default currency to EUR where the books are kept in euros. Define the fiscal year to match the consultant's financial year, including its start date, because the General Ledger export is cut by period. Confirm the tax templates for VAT rates and any reverse charge cases before posting. Changing the company abbreviation or fiscal year after transactions exist is disruptive, so settle these settings in a test site first.
Customer and supplier master data
The master data ZIP carries the debtor and creditor records the consultant needs to match postings in DATEV. Each customer and supplier should have a stable, unique number, a complete name and address, and the correct tax identifiers. Duplicate parties created during imports break matching later and are hard to correct once vouchers reference them. Clean the party records before the first export, and agree with the consultant whether they want party numbers from ERPNext or from their own numbering scheme.
Outgoing mail for the voucher route
Sending submitted vouchers to DATEV Unternehmen Online by email depends on a working outgoing Email Account in ERPNext. Configure the sending address and SMTP settings, send a test message to the consultant's DATEV intake address, and confirm that the message and attachment arrive in the correct DATEV client. Check which voucher types are sent and whether the consultant expects one mail per voucher or a batch. Your mail provider's sending limits and authentication rules apply, so verify them with the provider rather than assuming the default setup is sufficient.
Access and format agreed with the consultant
Settle the handover in writing before the first export. Confirm who at the consultant's office receives the vouchers and the General Ledger file, which DATEV Unternehmen Online access they hold, which period the first export covers, and who on your side is responsible for each run. Agree the export format, including the DATEV CSV layout and the master data ZIP contents, and run a trial export that the consultant imports successfully. Record the agreed settings so that later changes are visible to both parties.
Configure the DATEV Integration app step by step
This sequence takes an ERPNext site from a fresh install of the DATEV Integration app to a verified hand-off package for the tax consultant. Each step ends with a check the consultant or your own team can confirm before you move to the next one.
Install the DATEV Integration app
Install the app either from the Frappe Cloud Marketplace on a Frappe Cloud site or with the bench command line tool on a self-hosted site, then confirm it appears in the installed apps list for the site. The app is published by ALYF GmbH, so check the version against your ERPNext version before installing and ask the publisher which release supports your major version. Done means the app is listed for the correct site and the site loads without errors after a restart of the background workers.
Enter company and consultant settings
Open the DATEV settings for each company in the site and enter the consultant details, the consultant number and client number as your tax consultant provides them, and the fiscal year start. Ask your consultant to confirm each value in writing, because a wrong client or consultant number will cause imports to fail on their side. Done means the settings save without validation errors and the consultant has confirmed the identifiers.
Map ERPNext accounts to the DATEV account scheme
Agree with your consultant which account scheme your books follow, then map each ledger account in your chart of accounts to its DATEV account number. Review receivable, payable, bank, tax and clearing accounts first, because these carry most of the posting logic. Done means every account used in the test period has a DATEV number, and the consultant has reviewed the mapping list.
Submit a test voucher to the consultant mailbox
Submit one test voucher in ERPNext, such as a sales invoice or journal entry, and send it through the DATEV integration to the consultant's Unternehmen Online mailbox. Use a clearly marked test document so it can be identified later and does not affect live reporting. Done means the consultant confirms receipt in DATEV Unternehmen Online and can see the voucher and its attachment.
Run a General Ledger export for a closed test period
Choose a closed test period with known postings, run the General Ledger export in DATEV CSV format, and open the file in a spreadsheet program. Check the delimiter, column headers, date format, decimal separator and account numbers against the format your consultant expects. Done means the file opens without shifted columns, and the consultant confirms it imports cleanly into their DATEV system.
Reconcile account balances to the trial balance
Compare the balances in the exported General Ledger with the ERPNext trial balance for the same closed period, account by account. Investigate any difference by checking unmapped accounts, currency conversions and entries posted after the period close. Done means every mapped account balance matches the trial balance, and any remaining differences are documented and explained to the consultant.
Generate the master data ZIP for import
Export the DATEV report with master data as a ZIP file and hand it to the consultant with the General Ledger file. Ask the consultant to import it into their DATEV system and confirm that customer, supplier and account master data load without errors. Done means the consultant confirms the ZIP import, and you keep a dated copy of the files and the test results for your own records.
What each of the three outputs carries and when to use it
The DATEV Integration app produces three different outputs, and each one answers a different question for the consultant. Voucher email to DATEV Unternehmen Online sends individual submitted vouchers as the bookkeeping happens, so it suits a consultant who works from a continuous stream of documents in DATEV Unternehmen Online. General Ledger export in DATEV CSV format is a file for a defined period, so it suits a period handover where the consultant needs the full ledger for a closed month, quarter or year. The DATEV report with master data as a ZIP bundles the report with customer and supplier master data for import into the consultant's own DATEV system, which suits a consultant who books inside DATEV rather than in the portal. Confirm with the consultant which of these they actually ingest before you configure anything, because the wrong channel creates work on both sides.
The outputs overlap in content. A voucher sent by email may also appear in the period General Ledger export, and the master data ZIP may repeat accounts and parties already known to the consultant. Nothing in the app removes these duplicates across channels, so the bookkeeper must decide which channel is the record of truth for each period and mark the others as reference only. Partial exports are the other risk: a period export run before late invoices are submitted, or a voucher email that failed to send, leaves gaps that surface only at year-end review. Agree a cut-off date and a reconciliation step with the consultant, comparing voucher counts and totals per period against the General Ledger export before the handover is accepted.
How ERPNext accounts, parties and vouchers map to DATEV fields
This table compares each ERPNext record type with the DATEV field or export element it feeds, so you can see what the consultant receives. Read each row as a question to confirm with the consultant before the first export. The main takeaway is that account numbers, party numbers, voucher types and tax keys are configuration decisions that must be agreed and tested on a sample file.
| ERPNext record | DATEV target | What to confirm | Where mapping usually fails |
|---|---|---|---|
| Chart of Accounts entries | Account numbers in the General Ledger export (SKR or chart selected by the consultant) | Which chart the consultant uses and that each ERPNext account carries the agreed account number | Accounts created with default names but no matching DATEV number |
| Customer master | Debtor records in the master data ZIP | Debtor number range and whether the consultant wants ERPNext customer IDs or their own numbering | Duplicate or renamed customers producing different debtor numbers |
| Supplier master | Creditor records in the master data ZIP | Creditor number range and how supplier tax IDs and bank details are handled | Suppliers without a matching account or with incomplete address fields |
| Sales Invoice (submitted) | Voucher in DATEV Unternehmen Online, with document reference to the invoice number | Voucher type and whether the consultant expects invoice number as document reference | Drafts or cancelled invoices included by mistake |
| Purchase Invoice (submitted) | Voucher with supplier invoice reference | Whether the supplier's own invoice number or the ERPNext number is required | Missing supplier invoice reference on imported bills |
| Journal Entry (submitted) | Voucher with its own voucher type and document reference | Which journal types the consultant accepts and how reversals are shown | Manual entries posted to accounts without a DATEV number |
| Tax codes and VAT keys | Tax key on each posting line in the General Ledger export | Explicit confirmation of every tax template and key with the consultant, based on a sample export | Tax templates reused across rates or missing keys for reverse charge |
Choosing the export route for your consultant's setup
This route fits a consultant who works in DATEV Unternehmen Online and wants submitted vouchers delivered to them by email. The DATEV Integration app, published by ALYF GmbH on the Frappe Cloud Marketplace, sends submitted vouchers to DATEV Unternehmen Online this way, so the voucher flow runs continuously rather than as a period-end batch. Your team configures the recipient address and decides which voucher types go out.
- Artifacts to send: submitted vouchers delivered by email to the address your consultant provides for Unternehmen Online.
- Who uploads: the consultant's DATEV side receives and processes the vouchers, so your team does not upload anything manually on this route.
- Confirm in advance: the exact mailbox address and whether it is a per-client address in DATEV.
- Confirm in advance: which document types (sales invoices, purchase invoices, payments, journal entries) the consultant expects.
- Confirm in advance: how corrections and cancelled documents should reach them, since a reversed voucher must not be double counted.
Before go-live, agree with the consultant on a test voucher that they can match in their own system.
This route fits a consultant who imports data into a desktop DATEV system. Your team produces the General Ledger export in DATEV CSV format and the master data ZIP, which the consultant imports into their DATEV software. Files are produced for a defined period, so the period boundaries and the chart of accounts version must match what the consultant expects.
- Artifacts to send: the General Ledger export in DATEV CSV format and the DATEV report with master data exported as a ZIP file.
- Who uploads: the consultant imports both files into their desktop DATEV system. Your team hands over files, not database access.
- Confirm in advance: the fiscal year, the export period and whether the consultant wants monthly or year-to-date batches.
- Confirm in advance: the account chart and any SKR mapping the consultant uses, so account numbers in ERPNext match their master data.
- Confirm in advance: the handling of opening balances and whether they should be exported separately.
Ask the consultant to import a single period first and reconcile the total to your trial balance before importing the full year.
This route applies when one group runs several companies in ERPNext and each company has its own books, its own consultant or its own DATEV client. Each legal entity needs its own export, because a combined file would mix ledgers the consultant must keep apart. The setup decisions are made per company before the first file leaves the system.
- Artifacts to send: one General Ledger export and one master data ZIP per company, for the same period.
- Who uploads: the consultant for each entity, or a single consultant who holds several DATEV clients. Confirm which person performs each import.
- Confirm in advance: the company-to-client mapping, including the consultant number and client number for each entity.
- Confirm in advance: intercompany transactions, and whether the consultant expects them eliminated or booked in each entity.
- Confirm in advance: the currency and any foreign subsidiary treatment, since these change which accounts appear in each file.
Run the export for one entity end to end with its consultant before repeating the process for the rest of the group.
Protecting ledger data during the handover
Once books leave ERPNext for a tax consultant, the export files and the mailbox route become the exposure points. The cards below cover who can run exports, where files sit, how they travel and how long they live, with the company's data protection officer reviewing personal data in debtor records.
Restrict the DATEV role to finance
Limit the DATEV Integration role to the finance staff who prepare the handover, and keep it separate from general sales or stock roles. Review which users hold Accounts Manager or System Manager rights, because those roles can reach the same ledger data the export draws from. Confirm the role list with your ERPNext administrator before the first export and again after any staff change.
Limit who can trigger exports
Decide which named people may run the General Ledger export and the master data ZIP, and record who ran each one and for which period. An export is a full copy of posted accounting data, so a single approver for each handover is a sensible default. Ask the consultant which period and file format they need so that repeat exports are avoided.
Send vouchers only to approved mailboxes
When vouchers go to DATEV Unternehmen Online by email, route them from a shared finance mailbox rather than a personal account. Confirm the receiving address with the consultant in writing and check it before each send, because a mistyped address can expose invoices to the wrong party. Ask your IT team whether the outgoing mail server enforces TLS for these messages.
Store exports in controlled locations
Keep exported CSV and ZIP files in a restricted folder or document store with access limited to the finance team, not on desktops or shared drives open to the whole company. Turn on access logging where the storage supports it. Avoid attaching these files to general ERPNext records where broader user groups can read them.
Set retention and deletion rules
Agree with the consultant and your data policy how long export files are kept and when they are deleted once the handover is confirmed. Write the rule down, assign an owner and check it at each period close. Confirm whether your statutory retention periods require keeping the source records longer than the temporary export copies.
Check the transfer method against policy
Before the first handover, confirm that email with attachments, the consultant's portal and any other route meet your data classification rules and the consultant's own requirements. Ask whether files must be encrypted before sending and who holds the decryption key. Review personal data in debtor records with your data protection officer, since GDPR obligations may shape what the export should contain.
Why DATEV exports fail or do not match the books
This table lists the most common reasons a DATEV export is rejected or its totals differ from ERPNext, with the cause and fix for each. Use it before handover to the tax consultant, and check every row against the trial balance for the same period.
| Failure | Likely cause | Fix before handover |
|---|---|---|
| Rows rejected for unmapped accounts | Ledger accounts in the chart of accounts have no matching DATEV account number, so the export cannot place them in the consultant's chart | Confirm the account mapping with the consultant, add the DATEV account number to each ledger account, then rerun the export for the period |
| Missing customer or supplier master data | Parties were created without account numbers or required tax details, so the master data ZIP and postings lack the identifiers the consultant needs | Run a list of customers and suppliers without account numbers, complete the records, and regenerate the master data ZIP |
| Vouchers absent from the export | Sales invoices, purchase invoices or journal entries are still drafts and were never submitted, so they are not posted to the ledger | Filter for draft documents in the period, submit or cancel each one, then compare document counts with the ledger |
| Period mismatch with the fiscal year | The export date range does not align with the company's fiscal year or posting dates fall into a closed or adjacent period | Set the export range to the exact fiscal year start and end in the company settings, and check postings near the boundary |
| Character encoding problems in CSV | Names, addresses or descriptions with umlauts or special characters are altered when the CSV is opened and saved in a spreadsheet program | Keep the file unopened in a spreadsheet, or confirm with the consultant which encoding and separator their import expects before sending |
| Voucher emails not delivered | The outgoing mail setup is blocked, unauthenticated or limited by the mail provider, so vouchers sent to DATEV Unternehmen Online never arrive | Test the outgoing email account, confirm sender authentication with your provider, and check the sent log for each voucher |
| Totals differ from the books | Any of the above causes, or exports run at different times while entries were still changing | Compare debit and credit totals and balances per account against the ERPNext trial balance for the same period before handover |
Questions German companies ask before the first DATEV handover
What does the DATEV Integration app cost and what drives the effort?
The DATEV Integration app is published by ALYF GmbH on the Frappe Cloud Marketplace, and the price is set by the publisher, so confirm the current license terms with ALYF before you budget. Your costs fall into three groups: the app itself, the hosting that runs ERPNext, and the services to configure it. Effort rises with the number of companies, the account structure you need to map, and how clean your master data is. Ask any partner for a fixed-scope quote that lists the app license separately from implementation, so you can see which costs recur and which are one-time.
How long does a DATEV handover setup take?
Duration depends on how far your chart of accounts and customer and supplier records are from what the consultant expects. A company with a settled chart of accounts and a single legal entity usually needs far less work than one with several entities, multiple currencies or years of duplicate master data. Timing also depends on how quickly your tax consultant confirms the export format and the test period they want. Ask for a plan with separate milestones for mapping, test exports reviewed by the consultant, and the production handover.
Can our in-house finance team set up the DATEV export without a partner?
Yes, if someone on the team is comfortable with ERPNext accounting, can read the DATEV CSV layout your consultant uses, and has time to test with real periods. The work is mostly configuration and verification, not custom code. The risk sits in the details: wrong account mapping, missing tax codes, or master data that does not match what the consultant imports. Many teams keep the export in-house and bring in a partner only for a review of the first test run or for the audit of the mapping before the first real handover.
What must our company provide before the integration starts?
Plan to provide four things: a current chart of accounts with account numbers, a cleaned customer and supplier master list, the tax settings and VAT codes you actually use, and a named contact at the tax consultant's office who will review test exports. Duplicate customers, inactive suppliers and inconsistent account names will show up in the master data ZIP, so clean them before the first export. Ask the consultant which DATEV account structure they use, because that decides how your ERPNext accounts should be mapped.
Does the DATEV export replace the consultant's tools?
No. The DATEV Integration app sends submitted vouchers to DATEV Unternehmen Online by email, exports General Ledger entries in DATEV CSV format, and exports the DATEV report with master data as a ZIP file for the consultant's DATEV system. The consultant still runs their own DATEV software, reviews the data, prepares tax filings and makes the bookings they are responsible for. ERPNext remains your system of record for daily accounting, and the consultant receives the data in the format they can import.
How do we scope a fixed-price DATEV implementation with DeployOpen?
DeployOpen agrees the scope in writing before work starts. A useful scope names the companies and periods in scope, the accounts and tax codes to map, the export types you need (voucher email, General Ledger CSV or master data ZIP), the test periods, and who signs off each test. DeployOpen does not publish prices, so the quote follows from that written scope. Ask for deliverables, acceptance criteria and what happens if the consultant requests changes after testing. DeployOpen prepares the system and evidence, but the consultant and the tax authority remain responsible for the tax treatment.
Who is responsible if the exported data is wrong?
Responsibility is shared, and the scope should say how. The configuration of the export, the mapping and the test runs are the implementation partner's work. The accuracy of the books, the account and tax decisions, and the final filings belong to your company and your tax consultant. Before the first real handover, have the consultant review a test export against a known set of vouchers, and record who approved it. Keep the test evidence with your audit documentation.
What a DeployOpen engagement covers for DATEV handover
A DeployOpen engagement for DATEV handover prepares the ERPNext books so that your tax consultant can receive them cleanly, and it stops there. The work starts by confirming the ERPNext version and hosting model, since the DATEV Integration app has to be installed and tested on the same release that runs production. We also check which Frappe Cloud or self-hosted environment holds the site, who has administrator rights, and whether a closed test copy can be created for rehearsal. Confirm with your bookkeeper which ERPNext version is live and which fiscal year you intend to hand over, because both shape every later step.
Next comes a joint review of the chart of accounts and master data with your bookkeeper and the consultant's team. The point is to agree on account numbers, account types, cost centers, customer and supplier records, and tax templates before any file is produced, because DATEV expects those references to match the consultant's own setup. We then configure the account mappings and document each one, record who approved it, and run test exports for a closed period. Each test export is compared against the General Ledger in ERPNext and against the consultant's import result, and every difference is either corrected in the source data or explained in writing.
The last part is operational. DeployOpen documents a handover runbook that covers who triggers each export, where the files are stored, which period is exported, how voucher emails to DATEV Unternehmen Online are checked, and how a failed run is repeated. We then train the finance team on that runbook so the process does not depend on one person. Tax filings, statutory declarations and audit attestations remain the responsibility of your consultant, your auditor or your own management, and DeployOpen does not issue any of them. Ask any implementation partner to state that boundary in the written scope.
How DeployOpen scopes and delivers your DATEV handover
DeployOpen plans, implements, customizes, integrates, documents and supports self-hosted open-source platforms inside your own infrastructure, so the DATEV handover runs on ERPNext you control. We agree the scope in writing before work starts, then configure the DATEV Integration app against your chart of accounts, your consultant's requirements and your submitted voucher flow. Each step ends with documented evidence your tax consultant can check.
How we scope
- Written scope lists which voucher types, General Ledger periods and master data sets go to your consultant.
- We confirm with your tax consultant which DATEV version, export format and import steps their system expects.
- We record who in your organization approves submissions, sends vouchers and receives the export files.
How we build
- We configure the DATEV Integration app on your ERPNext site and map accounts, cost centers and tax codes.
- We test the voucher email path and the General Ledger CSV export against a copy of your books.
- We compare exported totals with ERPNext reports to confirm that balances and open items match.
How we hand over
- You receive a runbook covering monthly export steps, file naming, and who runs each step.
- We document the configuration keys, mail settings and account mappings used in your environment.
- We walk your finance and consultant contacts through a sample handover before the first live export.
How we support
- Ongoing support, upgrades and continuous testing are available as a retainer after handover.
- We review app and ERPNext release notes for changes that could affect the DATEV export before you upgrade.
- We re-run export checks after each upgrade, and we confirm version compatibility with your consultant.
