Process Comparison · Warehouse & Distribution
WMS or ERP inventory module: which does your warehouse need?
Two different problems, two different data models, two very different prices. What each solves, what the vendors publish, and where a purpose-built layer earns its place.
An ERP inventory module is a stock ledger: how much you have and what it is worth. A WMS is a movement director: where an item physically sits and who should pick it next. Buying the second when you only need the first adds cost and complexity without adding throughput.
Distribution and manufacturing companies routinely buy warehouse software to fix a problem that is actually a stock accuracy problem, or run for years on a stock ledger while pickers walk twice the distance they need to. The two are not interchangeable. Every price below comes from the vendor's own pricing page and is linked in the sources section.
What each one actually does
| Criterion | ERP inventory module | Warehouse management system (WMS) |
|---|---|---|
| Core question | How much do we have, and what is it worth? | Where exactly is it, and who picks it next? |
| Unit of record | Item and quantity | Item, quantity, bin location and task |
| Primary user | Purchasing, sales, finance | Warehouse operative and supervisor |
| Typical interface | Desktop screens and reports | Handheld scanner or phone, task by task |
| Optimises | Stock value, reorder points, availability | Travel distance, pick accuracy, throughput per shift |
| Traceability | Batch and serial at ledger level | Batch, serial and expiry at bin and movement level |
| Fails when | Pickers cannot find items without asking someone | The underlying stock data is inaccurate to begin with |
| Prerequisite | Item master and accurate counts | Everything above, plus addressed locations and scanning |
Published prices for both routes
| Option | What it covers | Published price |
|---|---|---|
| Katana Core | Inventory and manufacturing base, unlimited users, one location included | From $299/month |
| Katana Warehouse Management | Warehouse add-on to Core | $149/month |
| Katana Traceability | Traceability add-on to Core | $249/month |
| MRPeasy Starter | Warehouse and stock in the base tier | $49/user/month |
| MRPeasy Enterprise | Adds barcode system, multiple stocks, multiple sites, packing | $99/user/month |
| Odoo Standard / Custom | All apps included, inventory among them | €11.90 / €17.90 per user/month (yearly billing) |
| Business Central Essentials | Inventory and distribution | $80.00/user/month |
| Business Central Team Members | Light roles — read, approve, limited entry | $8.00/user/month |
| Acumatica | Distribution edition | Not published — consumption-based, quote required |
| KodDelta custom warehouse layer | Scan screens, picking logic, integration to your existing system | $3,000-6,000 (single process) / $8,000-15,000 (multi-module) |
Figures are the values shown on each vendor's own pricing page at the time of checking and vary by country and billing term. Acumatica states it prices on functionality and resources rather than user seats and requires a custom pricing review.
The pricing shape that catches people out
Warehouses are headcount-heavy, and that interacts badly with per-seat pricing. Every operative who scans is a user. Under per-user models, a warehouse with twenty operatives is twenty licences, every month, forever — and it is common for those twenty people to need only a fraction of the system's functionality.
Two published mechanisms mitigate this and are worth designing around. Microsoft's Team Members licence at $8.00 per user per month is intended for people who read records, approve, or enter limited data — a description that fits many warehouse roles, and getting the licence mix right is frequently the single largest saving available in a Business Central deployment. Katana takes a different route by including unlimited users in Core, so scanning headcount does not affect the bill at all; its warehouse capability then arrives as a $149/month add-on rather than a per-person cost.
The custom route removes the variable entirely: no per-user fee, no cap. Whether that outweighs the day-one cost is arithmetic over five years, and it usually turns on how many people hold scanners.
Barcodes: the prerequisite nobody budgets
A WMS is only as good as its scan data. Before comparing warehouse products, settle what your labels carry, because that decision shapes the data model and is expensive to change once labels are printed.
A conventional 1D barcode carries a single identifier and is the fastest thing to scan. 2D codes carry more: GS1 US states that beyond the product number, 2D barcodes can include data such as product variants and production or expiration dates, and can connect to online information through GS1 Digital Link standards. The same source describes Sunrise 2027 as a global transition from 1D UPC barcodes to 2D codes in retail, while noting that implementing all 2D capabilities by that date is not required and recommending a phased approach.
For a warehouse the practical question is simply how many fields you need per scan. One field means 1D is enough and faster. Batch, expiry and variant in a single scan means 2D. If you supply retail chains, the transition above is a reason to plan for 2D sooner rather than later.
Which one, in which situation
| Your situation | What you need | Why |
|---|---|---|
| One location, pickers know where things are | ERP inventory module only | You have a ledger problem, not a routing problem |
| Counts never match the system | Fix stock accuracy first | A WMS built on bad data produces confident wrong instructions |
| Multiple locations or bin-level addressing | Warehouse-level capability | Ledgers do not model bins or movement tasks |
| Batch, serial and expiry tracking required | Traceability capability (Katana add-on, MRPeasy Enterprise, or custom) | Published as a distinct tier or add-on in both products |
| 20+ people will hold scanners | Compare per-seat against unlimited-user and custom models | Headcount is the dominant line in warehouse software |
| Mis-picks are the main pain | Scanning discipline before software choice | Confirmation at the point of pick is what removes mis-picks |
| Your picking logic is genuinely unusual | Custom warehouse layer | Routing rules are where packaged products are least flexible |
| You already have an ERP you are happy with | Custom scan layer on top | Cheapest correct answer — keep the ledger, add the movement layer |
Where a custom warehouse layer earns its place
The most common and most economical pattern we build is not a replacement WMS. It is a scan layer on top of an ERP the company already owns and does not want to change: the operative scans on a phone or handheld, the movement is confirmed, and the existing stock ledger is updated through its API.
That works because the three things that decide warehouse software success are all in that layer. The scan screen has to close in about three seconds, with gloves on, under warehouse lighting — general-purpose screens rarely manage it. The picking rules are frequently company-specific and are exactly where packaged products flex least. The user count is high, and this layer carries no per-user fee.
KodDelta publishes its bands: $3,000-6,000 for a single-process solution such as a scan-and-confirm layer (2-4 weeks) and $8,000-15,000 for a multi-module system covering receiving, picking, packing and dispatch (4-8 weeks). Integration to an existing system is part of the project rather than a separate licence, and maintenance is optional at 12-25% per year.
Where this is the wrong answer: a single-location warehouse with a handful of staff and accurate counts. There, an ERP inventory module you already pay for is sufficient, and we will tell you that rather than sell a layer you do not need. Hardware is also outside our scope — we do not sell scanners.
Test your own situation in three questions
- Can a new starter find any item without asking a colleague? If yes, you do not have a routing problem and an ERP inventory module is enough. If no, that is exactly what warehouse-level addressing solves — and it is a real, measurable gain.
- What is the gap between your system quantity and your last physical count? If you cannot answer, fix stock accuracy before buying anything. A WMS layered on inaccurate data issues confident, wrong instructions all day.
- How many people will hold a scanner? Multiply that by the per-seat rate of each candidate, annually, and set it beside the unlimited-user and custom options. In warehouses this single calculation decides more comparisons than any feature list.
Bring those three answers and the first conversation is short — we can usually say within half an hour whether you need software at all, and if so which layer.
Sources
- Katana Pricing — Core and Warehouse Management add-on (katanamrp.com)
- MRPeasy Pricing — tier contents including barcode and multi-stock (mrpeasy.com)
- Odoo Pricing (odoo.com)
- Dynamics 365 Business Central Pricing (microsoft.com)
- Acumatica Pricing (acumatica.com)
- GS1 US — Sunrise 2027 and 2D barcodes (gs1us.org)
- KodDelta pricing and delivery bands
Sources checked in August 2026. Vendors change prices without notice; verify the linked page before deciding. Product names belong to their respective owners; KodDelta is not a partner or reseller of any vendor listed here, and does not sell hardware.
Frequently asked questions
What is the difference between a WMS and an ERP inventory module?
An ERP inventory module answers "how much do we have and what is it worth" — it is a stock ledger tied to purchasing, sales and accounting. A warehouse management system answers "where exactly is it and who should pick it next" — it directs physical movement by bin, wave and task. Most companies need the first; companies with real picking complexity need both.
What do the published options cost?
Katana publishes Warehouse Management as a $149/month add-on to Core, which itself starts at $299/month with unlimited users. MRPeasy places multiple stock locations, barcode scanning and packing in its Enterprise tier at $99 per user per month. Odoo includes all apps in Standard at €11.90 and Custom at €17.90 per user per month. Business Central Essentials at $80.00 per user per month covers inventory, with Premium at $110.00 adding manufacturing.
When is an ERP inventory module enough?
When your stock lives in one place, pickers know where things are, and mis-picks are rare. If someone can find any item without asking a colleague, you do not have a warehouse routing problem — adding a WMS at that point buys complexity rather than throughput.
When do I actually need warehouse-level control?
When any of these are true: more than one physical location, bin-level addressing, batch or serial traceability with expiry dates, wave or zone picking, or a mis-pick rate high enough that someone re-counts before dispatch. Each of those is a routing problem, and stock ledgers are not built to route.
Do I need barcodes to run a WMS?
In practice yes, because a WMS depends on knowing what was actually touched, not what someone intended to touch. Whether you use 1D barcodes or 2D codes depends on how many data fields you need per scan. GS1 US describes Sunrise 2027 as a global transition from 1D UPC barcodes to 2D codes in retail, and states 2D codes can carry data such as product variants and production or expiration dates.
When is a custom warehouse layer worth building?
When the picking logic is genuinely yours, when the scan screen has to be usable in three seconds with gloves on, or when the number of warehouse users makes per-seat pricing the dominant annual cost. KodDelta publishes $3,000-6,000 for a single-process solution and $8,000-15,000 for a multi-module system, with no per-user fee.
Start with the count, not the catalogue
Tell us your location count, your stock accuracy and how many people will hold scanners. We will say whether you need a warehouse layer at all — and which one.