ERP or accounting software: what is the difference and when do you need both
ERP runs the company’s operations: inventory, sales, orders and customers. Accounting software handles the accounts. Often, you need both, connected. Custom ERP costs 3 000-29 300 € based on 98 quotes we have prepared.
For companies where inventory, sales and accounting live in different programs and the data doesn't match.
Ивелин КириловChief Technology Officer (CTO) ·Managing editor:
Владислав БарковManaging Director· Updated The ERP system runs the company's operations as they happen: inventory, orders, sales, customers, production and team tasks. Accounting software handles the accounting afterwards: ledgers, VAT, social security contributions and reports to the NRA. A company with one location and no warehouse can manage with accounting software alone; a company where the warehouse, invoices and shop do not match needs an ERP that sends organised data to accounting. A custom ERP costs €3,000-€29,300, most often around €8,600, across 98 of our quotes as of 14 August 2026; the accounting software stays with the accountant.
We get this question in almost every first conversation, usually phrased like this: “We already have software-why do we need another one?” Below is the difference across six criteria, the products Bulgarian businesses use for each of the two jobs, examples from our clients where the answer was “your accounting software is enough”, and the systems you can open.
ERP System
Runs the company's operations: inventory, sales, orders, customers, production and service. The whole team uses it every day, from the moment of sale.
Accounting software
Handles accounting: entries, ledgers, VAT, payroll and reports to the NRA. It is used by the accountant after the documents reach them. Often you need both, connected without duplicate data entry.
Comparison by criteria
| Criterion | ERP System | Accounting software | Verdict |
|---|---|---|---|
| What it's for | Inventory, orders, sales, customers, manufacturing, service, reports for the owner | Accounting entries, VAT ledgers, payroll and social security contributions, annual reports | Different tasks |
| Who uses it | Manager, salespeople, warehouse, service, manufacturing, field team | The accountant, in-house or external | ERP is for the whole team |
| When the data is available | At the time of the sale, delivery or stock movement | After the documents reach the accountant, usually once a month | ERP, when you make decisions based on stock levels |
| What it issues | Invoices, pro forma invoices, delivery notes, quotes, protocols, in PDF | Records the issued documents in the accounts; some software also issues invoices | The invoice is issued in one place |
| Price | Custom-built: €3,000-€29,300 one-off, maintenance €100-€350 per month | Monthly subscription or licence per computer, for example Microinvest Delta SUB for 19,90 € per month excluding VAT | Accounting software is cheaper because it does less |
| Connection | Sends invoices, business partners and payments to the accounting software | Accepts documents in the format it supports, or the accountant enters them | Both together, connected |
Ready-made products our clients weigh up
The facts come from each product's public page, read on the date next to the link. A figure we could not read there is not included on the page.
| Product | What it is and how you pay | Who it is for | Source |
|---|---|---|---|
| Microinvest Delta Pro | Accounting software from Bulgarian developer Microinvest. A perpetual licence or a Delta SUB subscription for 19,90 € per month excluding VAT; TRZ i LS SUB is the same price. | The accounting firm or in-house accountant. This is the software that an ERP system most often needs to send invoices and business partner details to. | microinvest.net, subscription plans as of 14 October 2026 |
| Microinvest Sklad Pro | Inventory and sales software from the same developer. Sklad SUB and Sklad Light SUB cost 19,90 € per month excluding VAT; the subscription works only on the computer on which it was activated. | A company with one location that wants inventory and a cash register in ready-made software and is prepared to work with its documents. | microinvest.net, subscription plans as of 14 October 2026 |
| Odoo | An open-source platform where accounting is one of the apps. Standard is €11.90 and Custom €22.90 per user per month with annual billing for the first 12 months, then €14.90 and €27.90; all apps are included in one fee. | A company that wants inventory, sales and accounting in one ready-made platform and has a partner for implementation and Bulgarian-specific requirements. | odoo.com, plans as of 14 October 2026 |
When accounting software is enough
When you have no warehouse, production or many customers, and issue only a few invoices a month. When the software is used by one person, the accountant, and nobody else in the company makes decisions based on its data. When there is no online store, couriers or orders for someone to re-enter. Then accounting software is enough.
As soon as the owner wants to see today's figures, not a month later from the accountant, a system becomes necessary. The owner of a small business asked us for exactly that: revenue, expenses and cash flow on one screen, every day. A system like this is at the lower end of the range, starting from €3,000.
When you need an ERP connected to accounting
When inventory, sales and invoices do not match. At Pelikan DTM, the same product had different stock levels in three places, while the annual audit of 2 500 items took days and could not be verified. The custom system issues invoices, pro forma invoices, receipts and stock notes from one module, with VAT by rate and the value in BGN next to the amount in euro, while accounting receives organised documents instead of a pile.
A company that rents out containers works with Microinvest Delta Pro and told us that invoicing was “further down the list”: the containers are what matters. We proposed that the system issue the invoices, send reminders after 3, 7 and 10 days, and automatically send them to the accountant on the 5th and 10th of each month. This is the integration people most often need: not a replacement for the accounting software, but an end to re-entering data into it.
For a window manufacturer, the integration with Microinvest was a separate line in the quote, just like the drafting software: the ERP system manages quotes, inventory and both production facilities, while accounting stays where it is.
How the two systems work together
The connection depends on what the accounting product supports. The simplest option is a file: the ERP system exports the invoices, counterparties and payments for the month in the format the software imports, and the accountant loads them with one click. The better option is automatic: the document is sent as soon as it is issued. We check which of the two is possible with the person who maintains the accounting software before preparing the proposal, and record the answer in it.
In the Account-X solution for accounting firms, we have built bank reconciliation and invoice recognition; we have not connected submission to the NRA so far, and we do not promise it before we have done it. An online store connected to Microinvest Pro issues the invoice directly in the software for every order, so the same invoice is not entered twice.
Real systems and solutions you can open
Invoices, pro forma invoices and receipts in PDF with VAT by rate, euro and Bulgarian lev in one document, plus six reports with export to Excel.
Customers, VAT and social security deadlines, a document portal, bank reconciliations and tasks assigned by accountant.
Opens without registration: customers, deadlines, a document portal and the accounting firm’s invoices.
Contacts, projects, tasks, invoices, calendar and reports in one system.
You need an ERP if:
- inventory, sales and invoices do not match
- you can't see inventory, orders and tasks in one place
- orders from the online store are re-entered manually
- the owner waits for the accountant’s report before making a decision about today
Accounting software is enough if:
- you don't have inventory, production or many customers
- the system is used only by the accountant
- there are only a few invoices a month and you issue them from the same software
Next step
Considering “Custom ERP system”? Describe what you need.
You describe the project, we come back with questions and a price range, then a demo and a written proposal.
Frequently asked questions
Does an ERP replace an accountant?
No. ERP sends organised data to the accountant, while accounting, taxes and reports remain the accountant’s responsibility and stay in their software. The companies we work with keep their accountant and stop bringing documents by hand.
Does ERP integrate with accounting software?
It depends on what the accounting product supports: an import file that the accountant loads, or automatic submission of each document. We check this with the person who maintains the software before preparing the quote, and state exactly what will be submitted in it.
Can our accountant continue using Microinvest?
Yes, and usually it remains. The custom system issues the invoices and sends them to Microinvest, or exports the month in the format the software imports. We do the same with an online store that issues the invoice directly in Microinvest Pro when an order is placed.
Does ERP submit data to the NRA?
So far, we have not integrated submissions to the NRA, and we do not promise this in a quote before we have done it. We have built bank reconciliations and invoice recognition in Account-X; VAT ledgers remain in the accounting software.
Are invoices issued from the ERP or the accounting software?
From one place, and we decide that upfront. For a company with daily sales, the invoice is issued from the ERP at the moment of sale, with a number and PDF, and sent to accounting. With a few invoices a month, it is simpler to keep them in the accounting software.
How much does an ERP cost if we already have accounting software?
The same as without it: €3,000-€29,300, most often around €8,600, depending on the modules and integrations. The integration with the accounting software is a separate line in the quote because it is separate work, and it is often the smaller part of the project.
