Open Mercato + Subiekt GT/nexo
Sync or migration from the most popular ERP for small Polish companies
Subiekt GT/nexo is an ERP chosen by Polish SMEs for over 15 years — simple, cheap, well-understood by accountants. The problem comes at growth: no B2B portal, limited CRM, weak API. Many companies past 20-30 people face the choice — extend or change.
We have two integration scenarios with Subiekt: (1) parallel operation — Subiekt stays for accounting, Open Mercato adds CRM + B2B + Commerce, (2) migration — full switch to Open Mercato preserving historical data. We help with both.
When which option
- Parallel sync — when accountant knows Subiekt, it works, no point changing
- Migration — when Subiekt limits company growth (no B2B, no modern API)
- Sync for 1-2 years, then migration — typical 'evolutionary path' scenario
- Subiekt GT vs nexo — choice affects integration cost (nexo has better API)
Two-way data flow
Open Mercato → Subiekt
Sales invoices, warehouse documents, customers, reservations
Subiekt → Open Mercato
Payments, balances, purchase invoices, customer history (for migration)
How integration deployment looks
Five stages — from the first conversation to a working production integration.
- 01
Decision: sync or migrate
Analysis of current Subiekt usage, growth plan, team competencies. Recommendation in 2-3 days.
- 02
Export data from Subiekt
Subiekt GT: SQL Server backup + custom scripts. Subiekt nexo: REST API + XML export. Customers, products, invoices, warehouse docs.
- 03
Data cleaning and mapping
Customer deduplication (Subiekt often has duplicates), product category mapping, tax ID validation, historical error identification
- 04
Sync configuration or migration import
Sync scenario: daily two-way sync. Migration scenario: one-off import with validation.
- 05
Test period + go-live
For sync: 2-3 week parallel run. For migration: 1-2 weeks of live data tests, then switch.
Subiekt integration scenarios
15-person company - Subiekt for accounting, Open Mercato for the rest
Client keeps Subiekt for invoices/tax reports, Open Mercato adds CRM + B2B portal. ~30% annual time savings in customer service.
50-person company - migration from Subiekt to Open Mercato
Subiekt limits growth (no B2B, weak API). Migration in 8-12 weeks preserving 5 years of invoice history. ROI in 12 months.
Seasonal company - 2-year sync, then decision
Parallel sync gives time to evaluate Open Mercato without risk. After 2 years client decides: continue sync or migrate.
Integration cost
Sync Open Mercato - Subiekt GT: EUR 2,800 - 6,500. Sync with Subiekt nexo: EUR 2,300 - 5,000 (better API). Full migration: EUR 5,800 - 14,000 depending on scale. Time: sync 2-4 weeks, migration 6-12 weeks.
Frequently asked questions
Are Subiekt GT and nexo the same integration?
No. Subiekt GT uses SQL Server (Sferis) — we integrate via ODBC + Sfera API. Subiekt nexo has REST API — much more modern and cheaper to integrate.
Can I migrate 10 years of invoice history?
Yes, but rarely makes business sense. Standard: 2-5 years of active history. Older invoices archived from Subiekt as PDF and linked to customers in Open Mercato.
What about tax reporting during migration?
For sync period: each system reports separately. After migration: tax reports from Open Mercato or via integration with accounting system. No reporting gap.
Does the accountant need retraining?
In sync scenario - no. Subiekt stays as accounting 'frontend'. In migration scenario - yes, but we provide an Open Mercato accounting module that's intuitive and has chart of accounts compatible with Subiekt.