Custom ERP Development Cost (2026): Ranges by Scope, Module and Team Location

Custom ERP software development typically costs between $27,000 and $307,000 with an Eastern European team, and between $61,000 and $614,000 with a US onshore team, depending on modules and integrations. A typical mid-size ERP covering inventory, sales orders, purchasing, a QuickBooks sync, reports and data migration lands at about $39,000 to $179,000 at Eastern European rates.

We build custom ERPs and the accounting integrations around them, so these figures follow how engineers split an ERP into modules and hours. They are planning ranges, not a quote. Hours are our estimates for a typical scope; hourly rates are market ranges from third-party surveys: 2026 outsourcing rate surveys put Eastern Europe at about $35 to $80 per hour, North America at $80 to $180 or more and South and Southeast Asia at about $25 to $60. We use $80 to $160 for US onshore. This article is about building your own ERP; if you are pricing a packaged system such as NetSuite or Business Central, read our guide to ERP implementation cost instead.

Cost at a glance

Costs are hours multiplied by the low and high ends of each rate band. Calendar time assumes about 30 productive hours per engineer per week. Adding engineers shortens the calendar, but not linearly: ERP modules depend on each other, and someone on the business side has to answer questions at the same pace.

The low end of each row assumes clear processes, clean master data and a client team that makes decisions quickly. The high end assumes processes that are discovered during the build, messy stock data and strict accounting reconciliation.

What drives the cost

1. Modules and how they interact. An ERP is expensive less because of any one screen than because every module touches the same stock and money. A sales order reserves stock, a purchase order receives it, production consumes it, and accounting has to agree with all three.

2. Accounting integration. Most small and mid-sized companies keep QuickBooks or Xero as the ledger. A reliable two-way sync with ID mapping, conflict rules, retries and a reconciliation report takes 160 to 320 hours in our planning ranges. Our QuickBooks two-way sync guide explains where that time goes.

3. Units, pricing and costing rules. Unit conversions, landed costs, customer-specific price lists and costing methods are small in a requirements list and large in code and tests, because every rounding decision ends up on an invoice.

4. Data migration. Opening stock, open orders, vendors and items from spreadsheets or an old system need cleanup and a reconciliation that finance signs off. Plan for 80 to 200 hours.

5. Roles, approvals and audit. Purchase approvals, who can adjust stock, and a history of every change are expected in an ERP and touch every module.

6. Multi-entity and multi-currency. Several legal entities, currencies or warehouses in different countries multiply the rules for numbering, tax, transfers and consolidated reports.

7. Warehouse mobile. Barcode scanning for receiving, picking and counts needs a handheld app and offline handling, often 160 to 320 hours.

Use the estimator to price your own scope. Tick the modules you need, then switch the rate band and team size.

Cost by module

All hours include design, QA and project management. When you compare vendor estimates, check that each one does too.

Running costs after launch

Maintenance and small changes. A widely used industry rule of thumb puts annual maintenance at about 15 to 20% of the original development cost. For a $120,000 ERP that is $18,000 to $24,000 a year. ERPs sit toward the top of that range, because accounting APIs, tax rules and business processes keep changing, and every change needs regression testing against stock and money.

Hosting. A single-company ERP for a few dozen users runs on a modest cloud setup with a managed database, background job processing and backups. In our worked example we assume $500 per month. Strict uptime, reporting replicas or several regions raise it.

New modules. Most companies keep adding to a custom ERP after launch. Budget these as projects, separately from maintenance.

The packaged alternative trades these costs for licenses. Microsoft lists Dynamics 365 Business Central at $80 per user per month for Essentials and $110 for Premium, billed yearly. NetSuite does not publish prices; third-party purchase data suggests roughly $129 per user per month plus a base fee around $999 per month, which is an estimate, not a quote. Packaged ERP also carries implementation and partner costs, covered in our ERP implementation cost guide.

Custom vs off-the-shelf: the 3-5 year math

Here is a worked example over five years, licenses only for the packaged options.

• Business Central Premium, 25 users: $110 × 25 × 60 months = $165,000.
• NetSuite (estimate), 25 users: ($129 × 25 + $999) × 60 = $253,440.
• Custom ERP: a $120,000 build (inside the mid-size range at Eastern European rates), plus maintenance at 20% of the build, $24,000 a year or $120,000 over five years, plus hosting at $500 a month, $30,000. Total: $270,000, regardless of seat count.
• At 60 users: Business Central Premium reaches $396,000 and the NetSuite estimate $524,340, while the custom total stays at $270,000.

The math also leaves out costs that apply to both paths. Your own staff spend time in workshops, testing and data cleanup whether you build or buy. Training, process changes and a period of running old and new systems side by side cost the same either way. And both options need someone who owns the system after launch: an admin or partner for a packaged ERP, an engineering team for a custom one. What differs is how the bill grows. Packaged licenses grow with every user you add; a custom ERP’s cost grows with every change you ask for. A company that expects headcount growth and a stable process leans custom; a company with a small team and a process that keeps changing leans packaged.

At 25 users, licenses alone are cheaper than building. Add a packaged ERP’s implementation and the customization it needs to fit an unusual process, and the gap narrows or closes. Over three years the build looks worse still, because it is paid up front.

So a custom ERP is rarely the cheapest option for a small company with standard processes. It makes sense when your operations do not fit standard objects (production with unit conversions, configurable products, unusual fulfillment), when seat count is high, or when you want to keep QuickBooks and add only the operational layer it lacks. For packaged shortlists, see best ERP for small business, best ERP for manufacturing and best ERP for wholesale distribution.

How to get an accurate estimate

1. Map the flow of goods and money. Draw how an order moves from quote to shipment to invoice, and how stock moves from purchase to receipt to sale. Every arrow is a requirement.
2. Decide what owns each record. Which system is the master for customers, items, prices, invoices and payments. Ownership decisions drive integration effort more than anything else.
3. Export real data. Item lists, open orders and stock counts show how much cleanup migration needs.
4. Phase the scope. Ask for a lean core priced separately from later phases.
5. Run a paid discovery. Two to four weeks of process workshops and a prototype turn a range into hours per module with written assumptions.
6. Compare like with like. Check that each estimate includes design, QA, project management, migration and hypercare, and names the rate and team.

From our work

Our custom ERP system for an inventory and order-driven business brings inventory, order processing, vendors, purchasing and reporting into one platform on .NET 8, React and MySQL, with purchase orders and vendor data synced to QuickBooks. A record entered once is reused wherever it is needed. The client reports 20% faster order fulfillment and 40% faster report generation.

One Motion ERP is the internal system of a business that buys raw materials, runs production and ships orders. OSKI develops and supports it on .NET 7 and React: production and purchase orders, shipping, weights that convert between LB, KG, STON and MTON, Excel and PDF reports built with EPPlus and iText7, Hangfire background jobs, and a two-way QuickBooks sync that handles invoice date mismatches, tax and tariff rules, vendor mapping and duplicates. It shows why the “units” and “accounting sync” lines in the estimator carry real weight, and why maintenance continues long after launch.

Where OSKI fits

OSKI is a .NET and React engineering company with a team mostly in Ukraine. We build custom ERP systems and CRMs, QuickBooks integrations and integrations with e-commerce, CRM and logistics tools. Send the estimator selection with a short description of your operations and an engineer will reply with a written estimate and the assumptions behind it.