Open Mercato vs Subiekt GT/nexo - Comparison 2026

Last updated: March 2026

Subiekt GT and Subiekt nexo by InsERT are the most popular trade and warehouse management programs in Poland. They handle invoicing, inventory and retail sales well, and thousands of Polish businesses rely on them daily. For basic commercial operations, they're solid, proven tools.

The challenge comes when a business outgrows simple invoicing. Subiekt lacks built-in CRM, a B2B ordering portal, a modern browser-based interface and open APIs for integration. Adding these capabilities means buying separate tools that don't always work together seamlessly.

Open Mercato is an open-source platform that combines CRM, ERP and B2B Commerce in a single system. It runs in the browser, requires no Windows installation, and gives you full control over the source code. For Polish businesses that have outgrown Subiekt -it's the natural next step.

Comparison Table

Criterion	Open Mercato	Subiekt GT / nexo
Licence	Open source (free)	One-time licence (~PLN 1,000 / seat)
CRM	Built-in -leads, pipeline, contact history	None -requires a separate system
B2B portal	Built-in -online ordering for partners	None -requires a third-party solution
Hosting	Cloud or self-hosted (Linux/Docker)	Local Windows installation (server + workstations)
Open source	Yes -full source code access	No -proprietary software
Interface	Modern, browser-based, responsive	Desktop (Windows), classic look
Integrations	REST API, webhooks, any connection	Sfera API (InsERT), limited options
API	Open REST API	Sfera -paid add-on, local only

Cost Comparison

Users	Open Mercato (yearly)	Subiekt nexo PRO (first year)
10 users	~EUR 700 - 1,400 (hosting)	~EUR 2,300 - 3,500 (licences + InsERT Service)
25 users	~EUR 1,200 - 2,400 (hosting)	~EUR 5,800 - 9,300 (licences + service)
50 users	~EUR 1,800 - 3,500 (hosting)	~EUR 11,600 - 18,600 (licences + service)

* Open Mercato costs cover infrastructure (hosting). Subiekt nexo PRO costs based on InsERT pricing (2026) -one-time licence + annual InsERT Service subscription for updates. Does not include additional modules (e.g. Sfera, Gestor).

When to choose Subiekt

Small Polish trading company (1-10 people), mainly invoicing and warehouse
Local Windows installation is fine -no need for browser access
You don't need CRM or a B2B portal
One-time software budget up to PLN 10,000
Your accountant uses InsERT's Rachmistrz/Rewizor

When to choose Open Mercato

Growing beyond 10 people and needing CRM, B2B and better analytics
You want a browser-based system -no per-machine installation
You need a B2B portal so partners can place orders online
Open API and easy integrations with other tools matter to you
You're looking for a platform that scales with your business -no system swap every 3 years

Outgrown Subiekt? Time for the next step.

Book a free 30-minute call. We'll show how to migrate from Subiekt to Open Mercato with zero downtime.

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Frequently Asked Questions

What is the difference between Open Mercato and Subiekt?

Open Mercato is a modern open-source cloud system with CRM, ERP and B2B Commerce modules. Subiekt is a Polish invoicing and warehouse system that runs locally. Open Mercato offers a wider range of features and access from anywhere.

Can Open Mercato replace Subiekt GT/nexo?

Yes. Open Mercato covers Subiekt's functionality (invoicing, warehouse, orders) and adds CRM, B2B portal, automations and integrations. Data migration from Subiekt is included in our implementation.

How much does it cost to switch from Subiekt to Open Mercato?

Open Mercato implementation starts from EUR 3,500 for the Starter package. There are no per-user licence fees like with Subiekt nexo. Cost depends on scope and number of integrations.

Does Open Mercato work in the cloud?

Yes. Open Mercato runs in the cloud -access from any browser, no local installation. On-premise hosting is also possible. Subiekt GT only works locally, Subiekt nexo requires additional configuration.

Can I migrate data from Subiekt to Open Mercato?

Yes. We migrate customers, products, stock levels, order history and documents. The process is zero-downtime -Subiekt runs until the moment we switch to Open Mercato.