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ERP SaaS: cloud ERP vs on-premise, costs and migration

What cloud ERP covers, how multi-tenant, hosted and on-premise ERP differ, what 25 users cost at a published list price, and the migration risks to plan for.

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Your finance team closes the month in spreadsheets exported from an old accounting system, and someone has proposed “moving the ERP to the cloud”. You need to know what that means, what it costs and what can go wrong. ERP (enterprise resource planning) software keeps a company’s core records in one system: the general ledger, purchasing, inventory, orders and often projects. ERP SaaS is that same system run by the vendor and rented by subscription, instead of installed on your own servers.

The choice matters because an ERP sits under almost every other process. A bad migration stops invoicing, not just one team. This guide explains what cloud ERP covers, the three ways it is delivered, a cost example from a published price list and the migration risks to plan for. For the basics of the delivery model, see What is SaaS?.

ERP in plain terms

Think of a restaurant kitchen with one shared order rail. Every ticket goes on the same rail, so the cooks, the cashier and the person ordering tomorrow’s vegetables all read the same orders. Without the rail, each station keeps its own notes and the numbers never match at closing time.

An ERP is that rail for a whole company. A sales order reduces stock, creates an invoice and posts revenue to the ledger in one step, because every module reads and writes the same database. Typical modules:

  • Financials: general ledger, accounts payable and receivable, bank reconciliation.
  • Supply chain: purchasing, inventory and warehouse.
  • Sales and service: quotes, orders and invoicing.
  • Projects and manufacturing: in the products and editions that offer them.

Cloud ERP does not change what the modules do. It changes who runs the servers, who applies upgrades and how you pay.

Three ways to run an ERP

The US National Institute of Standards and Technology (NIST) defines SaaS as using “the provider’s applications running on a cloud infrastructure”. You do not manage the servers, the operating system “or even individual application capabilities”, apart from limited settings (NIST SP 800-145, September 2011). NIST also describes resource pooling, where the provider’s resources “are pooled to serve multiple consumers using a multi-tenant model”.

That definition separates three models that vendors often sell under the same word, “cloud”:

Question Multi-tenant ERP SaaS Single-tenant hosted ERP On-premise ERP
Who runs the servers Vendor, shared by many customers Vendor or a hosting partner, one instance for you You
Who decides when to upgrade Vendor, on its release calendar Usually you, within the vendor’s support window You
How deep you can customize Configuration and extension tools Deeper, sometimes including code changes Anything, including core code
How you pay Subscription per user Subscription plus hosting and services License, yearly maintenance, hardware and staff
Main risk Less room to change standard processes Upgrades postponed until they pile up Old versions fall out of support

The table summarizes how the three models usually work. It does not describe one vendor; the contract decides the actual terms.

The upgrade row is where you feel the difference. SAP describes S/4HANA Cloud Public Edition as “a ready-to-run cloud ERP” with “automatic upgrades”, and lists its major releases in February and August (SAP Learning). You test before each release. You do not choose whether it happens. In return, you never fall years behind.

What cloud ERP costs

Most ERP SaaS is priced per user per month, often with a cheaper license for people who only read or approve. Microsoft’s price list for Dynamics 365 Business Central (as of October 2026) shows three user types, each priced “user/month, paid yearly”:

  • Essentials: $80.00.
  • Premium: $110.00.
  • Team Members: $8.00.

Microsoft notes that these prices are informational and that the actual price appears at checkout.

Example: a distributor with 25 people. Twenty need full finance and inventory access on Essentials. Five only approve purchase orders and read reports. Assume Team Members licenses cover what those five do; check Microsoft’s licensing guide before you buy. At list price:

  • Full users: 20 x $80 = $1,600 a month.
  • Light users: 5 x $8 = $40 a month.
  • Subscription: $1,600 + $40 = $1,640 a month, or $1,640 x 12 = $19,680 a year.
  • If all 25 people got Essentials instead: 25 x $80 = $2,000 a month, or $24,000 a year.
  • Assigning the right user type saves $24,000 - $19,680 = $4,320 a year, which is 18% of the all-Essentials price.

The subscription is rarely the whole bill. Implementation partners, data migration, training and add-on apps usually come on top, and none of them appear on a vendor’s price list. Before you compare a subscription with the license you already own, ask for a written estimate of each one.

Migration: where ERP projects go wrong

The software is only one part of a migration; the data and the timetable are the others. Four risks deserve a line in your plan:

  1. Dirty master data. Duplicate customers, retired products and old account codes move with you unless you clean them first.
  2. Customizations with no cloud equivalent. Code added to an on-premise ERP over the years may have no place in a multi-tenant product. SAP, for example, says its public cloud edition is typically a strong fit for customers with “limited customization requirements”.
  3. Integrations. Banks, online stores, payroll and the sales system all connect to the ERP, and each connection must be rebuilt and tested. For one system that feeds an ERP, see CRM SaaS.
  4. Cutover timing. Switching in the middle of a period leaves two ledgers to reconcile. Switch at a period end and keep the old system read-only for audit.

Support deadlines set the timetable too. On February 4, 2020, SAP announced mainstream maintenance for its Business Suite 7 core applications “until the end of 2027”. Optional extended maintenance runs to the end of 2030, at a premium of two percentage points on the maintenance basis. SAP has since published a separate transition option for customers that move to its private edition before the end of 2030, with terms updated on October 13, 2026. If you run an older on-premise ERP from any vendor, find the equivalent date before you plan.

Checklist

  • List every module you use today, and every module you pay for but do not use.
  • Count users by type: full, light (approve or read only) and none.
  • List every customization and mark the ones the cloud product covers with configuration.
  • List every integration and the person who owns it.
  • Get the vendor’s release calendar and the testing window before each release.
  • Get written estimates for implementation, data migration and training.
  • Pick a cutover date at a period end, and keep the old system read-only afterwards.

Common mistakes

  1. Calling a hosted single-tenant system SaaS. Why it happens: both are “in the cloud” and both are billed by subscription. Instead: ask who decides when upgrades happen and whether your instance is shared. The answers tell you how much control and how much upgrade work you keep.
  2. Licensing every person as a full user. In the example, that costs $4,320 a year for 25 people. Why it happens: one license type is the simplest order to place. Instead: count light users before you sign, and check what each license type allows.
  3. Moving the data as it is. Why it happens: cleaning feels like a task for after go-live. Instead: clean and archive master data before the migration, while the old system is still the reference.
  4. Rebuilding old customizations by reflex. Why it happens: users ask for the screens they know. Instead: for each customization, ask whether a standard process in the new product does the same job.

For how per-user pricing compares with other structures, see SaaS pricing models. For where SaaS sits among the cloud service models, see SaaS in cloud computing.

Sources

In three sentences

ERP SaaS is a company’s shared record of finance, inventory and orders, run and upgraded by the vendor and paid for by subscription. At Microsoft’s list prices, 20 full Business Central users and 5 light users cost $1,640 a month, $4,320 a year less than licensing all 25 as full users. Plan the migration around clean data, fewer customizations, rebuilt integrations and your current vendor’s support deadline, because no subscription covers those parts for you.