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ERP for online merchants | Figures checked on 11.10.2026

What does an ERP for online merchants need to do?

An ERP for merchants with volume has to connect shop, marketplaces, warehouse, shipping, invoicing and the handover to your tax advisor on the same master data. At weclapp, the ERP Handel (retail) package covers these modules; it costs €163 per user per month with annual billing (weclapp list price, as of October 2026, net). There are no per-document or transaction fees. Carrier contracts, support packages and add-on products come on top.

wals.pro is a weclapp partner. The figures and examples on this page therefore describe weclapp; the yardstick is the module list, not the product.

Book a call: go through your merchant setup

The job of a merchant ERP

An order should run through a single system from the click in the shop to the posting, without anyone retyping data. That takes six core modules:

  • Shop integration for items, stock, orders and customers.
  • Marketplace integration for orders from multiple channels.
  • Warehouse management with stock, replenishment planning and purchasing.
  • Shipping with labels and tracking via the carriers.
  • Invoicing including e-invoices and payments.
  • Handover to your tax advisor.

If one of them is missing, you end up with an interface or Excel list where stock levels can drift apart or documents can go missing. If you supply businesses, you also need prices per customer: according to the feature table, weclapp supports tiered prices, customer-specific prices and discounts.

The building blocks at a glance

What each building block covers at weclapp and from which package.

BausteinDas braucht der HandelLaut weclappAb Paket
ShopArtikel, Bestand, Aufträge, KundenShopify, Shopware 6, WooCommerce u. a.nur Handel
MarktplätzeBestellungen aus allen KanälenAmazon, eBay, Kaufland.de u. a.nur Handel
LagerBestand, Einkauf, ChargenLagerverwaltung, Disposition, Bestellwesennur Handel
VersandLabels und Tracking je CarrierDHL direkt, weitere Carrier über eine Zusatzanbindungnur Handel
ZahlungZahlungstransaktionen abrufen und zuordnenPayPal, Stripe, Klarna (Austausch von Zahlungstransaktionen)alle Pakete
RechnungE-Rechnung schreiben und empfangenXRechnung, ZUGFeRD, UBLalle Pakete
SteuerberatungStrukturierte ÜbergabeDATEV-Export, Zugang gratisalle Pakete
BetriebDatenortHosting ausschließlich in Deutschland–

Which building blocks are in which package

Shop and marketplace integration, warehouse, replenishment planning and shipping are in the ERP Handel package (package card on the pricing page); e-invoicing, DATEV export, payment service providers and tax advisor access are in all packages. For merchants, ERP Handel is therefore the one that counts. For shipping, weclapp's industry page names DHL as a direct interface (as of October 2026); DHL requires a business customer contract, and the interface applies to customers from Germany.

Example: Shopify, Amazon and Kaufland with 3,000 orders

Example calculation, fictional: a retail business sells via Shopify, Amazon and Kaufland, has 3,000 orders per month, four users and two warehouses. Target picture for the day: orders from all channels in the same order backlog, label, invoice, export to your tax advisor. What runs in which direction per marketplace is something you clarify up front (stock and orders).

The calculation uses the weclapp list price, as of October 2026, net, assuming four users without a support package and add-on products: 4 × €163 = €652 per month with annual billing, 4 × €179 = €716 with monthly billing. The number of orders does not appear in this calculation, the number of users does. Plug in your own values.

Invoicing and tax advisor

According to weclapp, the system writes e-invoices in XRechnung, ZUGFeRD and UBL and captures incoming e-invoices. For the handover, the pricing page lists a DATEV export; according to the DATEV marketplace, weclapp offers the interfaces Rechnungsdatenservice 1.0 (invoice data service) and Buchungsdatenservice (booking data service). On request, your tax advisor gets free access to weclapp. Which route suits your firm is something you clarify with your tax advisor.

On the obligation: domestic businesses have had to be able to receive e-invoices since 01.01.2025. For invoices to other domestic businesses, issuers with more than €800,000 in prior-year turnover must issue e-invoices from 01.01.2027, all others from 01.01.2028. Invoices to consumers, small amounts up to €250 and other cases are exempt. The primary source is the German Federal Ministry of Finance FAQ, as of March 2026. This does not replace tax advice.

Price, operations and load

weclapp's pricing model depends on the team, not on documents. The industry page states "No costs for interfaces and their support". The weclapp app in the Shopify App Store is free to install; you only pay for the weclapp license, which weclapp bills separately from Shopify. Email support is included free in all packages; phone and live chat support are available through optional, paid support packages (Bronze, Silver, Gold).

Operations: weclapp hosts data exclusively in Germany (per the pricing page). For the API, weclapp does not state fixed rate limits but does limit concurrent requests per tenant: excess requests currently wait up to 30 seconds in a queue, after which HTTP 429 follows. weclapp does not state a throughput figure, and we do not promise one. More on load on peak days: Black Friday.

The key figures

€163
per user per month, ERP Handel with annual billing (weclapp list price, as of October 2026, net)
€179
per user per month with monthly billing (weclapp list price, as of October 2026, net)
No
per-document or transaction fees; support packages and add-on products come on top
30 days
free trial, ends automatically

Source: weclapp pricing page (list prices, as of October 2026, net). Figures checked on 11.10.2026.

The seven detailed questions

Every question has its own page.

What does an ERP cost at 500 to 10,000 orders?

The price depends on the number of users, not the number of orders. Four fictional profiles show the monthly bill.

Read the answer

Pro Beleg oder pro Nutzer:in?

Beide Preismodelle im Wachstum gerechnet: wann pro Beleg günstiger ist und wann es kippt.

Zur Antwort

Invoicing tool or ERP: what do you need?

Five check questions help you decide. If all you need is invoicing, labels and DATEV export, a lean tool may be enough.

Read the answer

How do I switch ERP while the shop keeps running?

Four phases up to parallel operation with a cutover date. The duration depends on interfaces and master data.

Read the answer

Will my ERP hold up on Black Friday?

weclapp does not state an upper limit for orders per day, and we do not promise one. Excess requests currently wait up to 30 seconds, then HTTP 429 follows.

Read the answer

How do I keep stock in sync across all channels?

Shopify receives stock every 5 minutes once you switch on the automation. That does not completely rule out overselling; a reserve per item reduces the risk.

Read the answer

How do I reconcile payouts from PayPal and others?

Invoice, payment and payout from the payment service provider are three separate processes. How you book them is something you clarify with your tax advisor.

Read the answer

Wholesale: how do I model prices and payment terms?

Tiered prices, customer prices, discounts and payment terms: what weclapp offers according to the pricing page and help, and what to watch for.

Read the answer

Welches ERP bindet mehrere Versanddienstleister an?

weclapp bindet DHL direkt an, Fulfillment 4 weclapp mehr als 14 Versanddienstleister samt Speditionen. Der Vergleich zeigt, was das am Packplatz bringt.

Zur Antwort

wals.pro as a weclapp partner

wals.pro is listed in weclapp's partner directory. weclapp's partner page shows three certificates: Basic, Onboarding and Warenwirtschaft (inventory management).

We support retail businesses with the rollout. Fulfillment 4 weclapp is built for the packing station with multiple carriers, and Zahlungsabgleich 4 weclapp matches payments against open items in weclapp and books clear-cut cases. More about us as a partner is on Your weclapp partner.

Who is this relevant for?

This page is aimed at online merchants and wholesalers with multiple channels, a warehouse and a team.

When is it not a fit?

A fit

  • You sell via shop and marketplace and have your own warehouse.
  • Several people work with the same data for ordering, warehouse, purchasing and accounting.
  • You want a pricing model that bills per user rather than per document.
  • Your tax advisor should get structured data instead of Excel lists.

Not a fit

  • You have one channel, one person and only need invoicing, labels and DATEV export. A lean tool can be enough then; run both options with your own numbers.
  • Your team is large and the number of orders is small. Then it is worth comparing against a model that bills per document.
  • You need warehouse control with storage-location logic across several sites. Then check during the trial whether the warehouse management maps your processes.
  • You sell via Amazon Vendor Central or on Kaufland storefronts outside Germany: the weclapp documentation does not list these as supported. For eBay, the documentation (as of 2021) describes order import, status feedback and listings; whether your need, such as a stock sync, is covered is something you clarify per channel up front.
  • You expect a switch at the push of a button. Master data and testing take time.

Frequently asked questions

What is the minimum an ERP for online merchants must be able to do?

At least six things: shop integration, marketplace integration, warehouse management with purchasing, shipping labels, invoicing including e-invoices and payments, and the handover to your tax advisor. At weclapp, according to the feature table, marketplace integration, warehouse management and shipping carriers are only in the ERP Handel package; e-invoicing, DATEV export and tax advisor access are included in all packages.

From how many orders does an ERP pay off?

There is no reliable fixed threshold. What matters is the number of channels, warehouses and users, whether you purchase and plan replenishment, and how much manual work sits between shop, shipping and accounting. If all you need is invoicing, labels and DATEV export, a lean tool may be enough. Five check questions on this are on the page "Invoicing tool or ERP: what do you need?".

What does weclapp ERP Handel cost for a retail business with four users?

According to the weclapp list price, as of October 2026, ERP Handel costs €163 per user per month with annual billing and €179 with monthly billing, both net. For four users that is €652 or €716 per month (example calculation). Support packages, setup and add-on products come on top as needed. There are no per-document or transaction fees.

Does weclapp connect Shopify and marketplaces?

Yes, with limitations. Shop and marketplace integration is in the ERP Handel package (see table). The weclapp documentation does not list Amazon Vendor Central as supported, for Kaufland.de only the German storefront, and for eBay the documentation (as of August 2021) describes order import, status feedback and listings; it does not describe a stock sync there. Whether your need is covered is something you clarify up front.

Which shipping and payment providers can be connected?

According to weclapp's industry page, DHL is connected directly; this requires a business customer contract. For payment services, weclapp supports PayPal, Stripe and Klarna, among others, for exchanging payment transactions. Fulfillment 4 weclapp connects further carriers such as DPD, GLS and FedEx as well as freight forwarders directly and adds scan capture and multiple labels per delivery. Whether your carrier is included is something you clarify up front in a call.

How does the tax advisor get the data?

Via the DATEV export, using Rechnungsdatenservice 1.0 or Buchungsdatenservice, among others. On request, your tax advisor can also get free weclapp access. Which route fits depends on the firm. Agree the approach with your tax advisor.

Can I try weclapp before I commit?

Yes. According to the pricing page, the trial is free for 30 days and ends automatically. A monthly license can be cancelled with one month's notice; longer terms only at the end of the term. Use the trial with real items and sample orders from your shop, not just demo data.

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Contracts, tickets, time and invoices for IT service providers and MSPs, with a calculation scheme per team size. Read more

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Your weclapp partner

Rollout, interfaces, support and plugins from wals.pro as a weclapp partner. To the partner page

Go through your merchant setup in one call

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