Universal bookkeeping-CSV → DATEV-CSV bridge: drop in any export from WISO MeinBüro, Papierkram, Norman.finance, Stripe, PayPal, n26, or your custom Excel — get a clean DATEV-Buchungsstapel CSV ready for your Steuerberater. No more 'nur via StB' gates. €5/mo or €19 one-shot.

What we ship

**Core features (MVP)**

• One-click OAuth connectors to Stripe / PayPal / Wise + drag-drop CSV upload for WISO MeinBüro / Papierkram / Norman.finance / any Excel
• Mapping rules engine: deterministic parsers for top-10 sources + AI fallback (Claude Sonnet) for unknown column formats; user confirms mapping in UI
• DATEV-CSV 1.0/4.0 Buchungsstapel export (ZIP containing EXTF_Buchungsstapel.csv + EXTF_Stammdaten.csv per DATEV Format-Beschreibung)
• Founder-self-service UX — standard SaaS onboarding in 3 minutes, no partner-program registration, no Steuerberater-cabinet workflow
• Schedule auto-pull (€5/mo unlimited): nightly Stripe/PayPal API pull → ready DATEV-ZIP in inbox on the 1st of every month

**Primary user flow**

1. User connects a source (OAuth Stripe / PayPal / Wise) or drag-drops a CSV from WISO / Papierkram / Excel

2. Mapping screen: deterministic parser auto-detects columns; for unknown formats AI proposes a mapping that the user confirms or edits

3. Buchungsstapel preview: table with SKR03/SKR04 Konten + Steuerschlüssel; user can edit individual rows

4. Export → DATEV-ZIP downloads; optional one-click email to the Steuerberater

**What it looks like**

• **Landing**: "DATEV-Export ohne €32.90 Lexoffice XL — €5/Monat oder €19 one-shot". Hero shows 3 source logos (Stripe / PayPal / WISO MeinBüro) → arrow → DATEV logo. Under the hero: a 4-tab demo (Stripe/PayPal/WISO/CSV) showcasing the mapping screen. Trust badges: "DATEV-Format-Lizenz public", "7d auto-purge", "DPA inkl. Steuerberater-Klausel". Comparison table vs Lexoffice XL / Konvertax / Convert2Fibu.
• **Main app**: left panel — connected sources + saved mapping rules. Center — stepper wizard (1. Source → 2. Mapping → 3. Preview → 4. Export). Top bar: current period (Monat/Quartal/Jahr) + Mandant switcher when multiple entities are connected. Inline AI suggestions in the mapping step with a "Confidence: 87%" indicator.
• **Output**: ZIP file `DATEV_Export_2026-04.zip` containing `EXTF_Buchungsstapel.csv` (1.0 or 4.0 format selectable) + `EXTF_Stammdaten.csv` + `mapping_rules.json` (re-usable for future months). Optional signed PDF summary report for the Steuerberater.

**MVP build plan** — 9 days

Source signals

• **SIG-20260425-dach-micro-saas-utility-datev-export-via-stb** — "WISO MeinBüro: DATEV-Export — Nur via StB" (SINGLE, structural)
• **SIG-20260425-dach-micro-saas-utility-multi-company-blocker** — "Geht nicht mit einem Account" (RECURRING via independent comparisons)
• **SIG-20260425-dach-micro-saas-utility-lexoffice-price-fatigue** — DATEV-Export gated in higher tiers across category (RECURRING)
• **SIG-20260425-dach-micro-saas-utility-circula-single-channel-distribution** — partner-led DACH B2B distribution insight (validates DATEV-Partnerprogramm channel)

Reasoning

Three signals point to a structural gate-pattern in DACH bookkeeping software: WISO MeinBüro requires the StB to extract DATEV, Lexoffice locks DATEV-Export in their XL tier, and multi-company users pay 2-3x the price. We don't compete with full-bookkeeping suites — we're the **bridge** between them and DATEV. User keeps their preferred WISO/Papierkram/Stripe and pays us €5/mo to skip the €50-150 StB-clerical fee per export, or to skip the €32.90 Lexoffice XL upgrade. Stack is clean (DATEV-CSV format is public spec, top-10 source parsers are deterministic, AI is a fallback for unknown column-mappings). The 9-day build is realistic for solo. Existing converters target Steuerberater-cabinet workflows, not end-user freelancers — which is our wedge.

Quick competitive read

5 profiled competitors (CMP files):

• **Konvertax** — €4.90/conversion bank-statement only; complementary tool, not direct competitor.
• **Convert2Fibu** — €19+/mo Steuerberater-cabinet targeted; we're end-user self-service.
• **GetMyInvoices** — €9-89/mo incoming-invoice aggregator with DATEV; perpendicular to our outgoing-bridge.
• **Norman.finance** — €14.90 Premium full-bookkeeping with DATEV; complement (we bridge from non-Norman tools).
• **KontoCSV.de** — €2.99/conversion PDF-statements only; partnership candidate.

Market density: **medium** — 5 active players, but the specific SaaS-source-aware bookkeeping → DATEV self-service angle is uncovered. Our wedge: bring-your-own-CSV from any tool, self-service for end-user freelancer (not Kanzlei). Competitive_pressure: 4 (category alive but uncovered specifically).

Initial pricing hypothesis

€0 trial (1 export, 50 rows) → €19 one-shot (full export, 5000 rows) → €5/mo unlimited exports + Stripe/PayPal API auto-pull → €15/mo Multi-Mandant for serial founders. Below the developed-tier $10-100 band intentionally because we're a bridge, not full-bookkeeping.

Distribution hypothesis

SEO long-tail ("DATEV Export selbst", "Stripe DATEV", "Papierkram DATEV Wrapper") + r/selbststaendig technical community recs + Steuerberater-channel partnerships (progressive StBs love clients self-serving) + DATEV-Partnerprogramm direct listing (per SIG-circula one-partner-ARR pattern).