- ERP integration timelines depend on scope, ERP access, data ownership, data quality, connector choice, and testing.
- Settling source-of-truth decisions early shortens projects more than any technical choice.
- Phasing (inventory and orders first) usually gets a working integration live sooner.
There is no honest single number for how long an ecommerce ERP integration takes. The schedule is set by a handful of decisions and dependencies that are usually visible in the first few weeks of discovery. Teams that surface those early tend to get a realistic plan; teams that skip them tend to discover them during testing, which is the most expensive place to find them.
The short answer: scope, access, and data quality set the pace
Most of the calendar time in an ERP integration is not spent writing connector code. It is spent agreeing on which system owns each piece of data, getting reliable access to the ERP, cleaning up records that don't map cleanly, and testing real order scenarios end to end. A narrow integration (for example, inventory and order export only) moves much faster than one that also covers pricing, customer accounts, fulfillment status, returns, and financing.
Timeline drivers to assess before committing to a date
1. Which data flows are in scope
Each flow (products, inventory, pricing, orders, customers, shipments, returns) adds mapping, edge cases, and test scenarios. List them explicitly and decide which are needed for launch and which can follow in a second phase.
2. ERP access and API maturity
Some ERPs expose modern, documented APIs; others rely on file exports, database views, or vendor-specific middleware. Waiting on credentials, sandbox environments, or vendor support tickets is one of the most common sources of delay, and it is largely outside the development team's control.
3. Source-of-truth decisions
If the business hasn't decided whether the ERP or the ecommerce platform owns pricing, availability, or customer records, development stalls while those decisions are made. Settling ownership up front shortens the project more than any technical choice.
4. Data quality and catalog complexity
Missing SKUs, inconsistent units, and products with many configurable options all add cleanup work. Industries with complex catalogs feel this most. In furniture ecommerce, for example, special-order items, fabric and finish options, and multi-location stock make mapping and availability rules noticeably more involved than a simple single-warehouse catalog.
5. Middleware versus custom connector
An off-the-shelf connector or integration platform can shorten initial setup but may need customization for non-standard workflows. A custom integration takes longer to build but can fit the business process exactly. The right choice depends on how standard your processes are.
6. Testing and cutover
Plan time to run realistic orders, partial shipments, cancellations, and returns through both systems, plus a reconciliation period after launch. Cutover planning (what happens to in-flight orders, when syncing starts) is often underestimated.
How phasing changes the schedule
Breaking the work into phases usually gets a working integration live sooner. A common pattern is to launch with inventory and order export, then add customer sync, fulfillment updates, and returns once the core flows are stable. Each phase gets its own testing window instead of one large, risky launch.
What an ERP–Shopify connection adds to the plan
When the storefront is Shopify, the plan also needs to account for Shopify API rate limits, webhook reliability, and how the store handles inventory across locations. Retailers running a furniture ERP such as STORIS alongside Shopify have specific mapping and order-routing considerations; Endertech's Shopify and STORIS integration page covers how that connection is approached.
Questions that produce a realistic estimate
Which data flows are required at launch, and which can wait?
How does the ERP expose data, and is a sandbox available?
Who owns pricing, inventory, and customer records?
How clean and consistent is the current product and SKU data?
Will you use a connector, middleware, or a custom integration?
How will in-flight orders be handled at cutover?
With those answers, an integration partner can give a scoped estimate with clear assumptions rather than a guess. Without them, any timeline is a placeholder.