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Vertex tax platform

Vertex ERP Integration Specialists

Tax calculated accurately, compliant and auditable every order. iWeb connects Vertex into your commerce checkout and ERP invoicing with governed product taxability, exemption rules, rate updates and reconciliation monitoring. Works with Adobe Commerce, Magento Open Source, Shopify Plus, BigCommerce and other storefronts.

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Works with - Adobe Commerce · Magento Open Source · Shopify Plus · BigCommerce · Other storefronts
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00 · At a glance

Vertex at a glance.

Category
ERP · finance
Role in the estate
The system of record for stock, pricing, customers, credit and orders - the storefront is a view over what the ERP already believes to be true.
Commonly connects with
Commerce platforms · PIM · product data · Middleware · iPaaS · automation · OMS · order management
Typical use cases
Calculate sales tax and VAT at checkout based on buyer location and product taxability · Handle tax-exempt customer accounts and reseller certificates across jurisdictions · Reconcile tax amounts in invoices against Vertex calculations for audit and finance closure · Manage rate changes and jurisdiction rule updates without manual line-by-line edits
Relevant services
BuildSupportPIM and Data
01 · What you get

What a Vertex integration gives you.

Compliant tax calculation at scale

Every order is taxed by the correct jurisdiction rules without manual intervention. Rate updates and rule changes apply on schedule, reducing risk of non-compliance and audit failures.

Finance reconciliation and audit trails

Tax amounts on invoices match Vertex calculations and are traceable back to the original order and location. Finance teams can close tax accounts and satisfy audit requests without rework.

Predictable tax experience at checkout

Customers see accurate tax before paying. Exemption certificates are validated in real time. Tax-exempt customers do not see tax in their receipt, reducing support friction.

Operational visibility across orders

Customer service and finance teams can see why an order was taxed a certain way, track refunds and adjustments, and identify patterns of miscalculation or rule drift.

02 · When it's worth it

Where a Vertex integration earns its place.

If two or more of these are true, the integration usually pays for itself quickly.

Calculate sales tax and VAT at checkout based on buyer location and product taxability
Handle tax-exempt customer accounts and reseller certificates across jurisdictions
Reconcile tax amounts in invoices against Vertex calculations for audit and finance closure
Manage rate changes and jurisdiction rule updates without manual line-by-line edits
Support cross-border and multi-currency orders with local tax treatment
03 · The limits

Where off-the-shelf connectors fall short.

Vendor connectors are fine for simple cases. Here's where the real ones need more.

Product taxability hardcoding

Vertex expects taxability flags on product records in commerce, but commerce platforms often store only SKU and price. Without a PIM or master-data layer feeding these attributes, taxability codes must be manually maintained in multiple places or abandoned to defaults.

Exemption certificate management

Tax-exempt customers need valid certificates on file before purchase. Vertex can validate them, but commerce platforms typically lack a governed workflow to collect, validate, expire and apply exemptions at checkout. This often falls back to manual account flags or spreadsheets.

Multi-entity and allocation rules

Vertex can calculate tax, but rules about which legal entity invoices an order, how tax is allocated across locations, and which jurisdiction's rules apply require integration logic beyond the tax engine itself. Commerce platforms do not usually own this logic.

Rate-change deployment and testing

Tax-rate files from Vertex are refreshed regularly, but testing them safely in commerce before cutover is not automated. Rate changes that miss the deployment window or apply to the wrong effective date can trigger non-compliance or incorrect refunds.

Reconciliation audit trails

Vertex calculates tax at transaction time, but tying that specific calculation back to the order, invoice and payment months later requires audit logs that commerce platforms and ERPs do not share by default. Regulatory demands often exceed what the systems log natively.

03b · Honest limits

When Vertex may not be the simplest fit.

A short, honest list. Not a warning; just where a different shape of system usually costs less to run.

The customer problem is on the storefront, not in the back office
Insisting on real-time syncs everywhere without a business reason
No agreed ownership of stock, pricing or customer records across systems
Treating the ERP as a black box behind an API rather than a system with rules
04 · The real work

Tax accuracy and compliance depend on whether taxability codes, exemption rules and rate changes are owned and versioned in one place or scattered across commerce, tax engine and ERP.

05 · Where it sits

Where this integration sits in your estate.

Vertex holds the commercial record. The iWeb integration layer manages the rules, mappings, monitoring and exceptions. The commerce platform presents the customer-facing experience. The estate map helps agree ownership before anything is built.

No platform lock-in. We integrate Vertex with the commerce core you already have, or the one you are moving to.

System of record
Source / owner
Vertex
Tax calculation and compliance engine for orders across jurisdictions
  • Tax rate tables by jurisdiction
  • Tax-rule updates and effective dates
  • Real-time tax calculation per order and line
  • Exemption certificate validation
iWeb integration layer
Customer-facing commerce
Commerce platform
Adobe CommerceMagento Open SourceShopify PlusBigCommerceOther storefronts
  • Checkout user experience and tax display
  • Order capture and tax amount recording
  • Customer exemption status at purchase
  • Fallback behaviour if Vertex unavailable
Connected neighbours
Integration layer
ERP
Owns product master taxability flags, customer exemption records, and invoice reconciliation; receives calculated tax amounts for posting.
Integration layer
PIM
May own product-taxability attributes if product data is centralised; syncs those attributes to commerce for checkout and to Vertex for calculation.
Integration layer
OMS / WMS
Receives orders with final tax amounts; uses tax data for invoicing at shipment or delivery.
Integration layer
Finance and compliance
Owns exemption-certificate policies, tax reporting by jurisdiction, and audit-trail review; reconciles Vertex calculations against ERP invoices.
Two-way sync where relevant
06 · Surrounding systems

Systems this integration usually sits next to.

Examples, not a closed list. iWeb is platform-agnostic on both sides: we wire this integration into whatever ecommerce platform and surrounding systems your estate already runs.

Ecommerce platforms (examples)
  • Adobe Commerce
  • Magento Open Source
  • Shopify Plus
  • BigCommerce
  • Other storefronts
Surrounding systems (examples)
  • NetSuite
  • SAP
  • Sage Intacct
  • Infor
  • PIM
  • OMS
  • WMS
Not sure?

Not sure if this works with your stack?

Tell us what you’re using and what needs to connect. We’ll give you a straight view on what’s possible, what might be awkward, and the safest way to approach it.

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07 · Data flows

The data flows we wire.

Each flow has a direction and an owner. We agree both before a line of code is written.

→Into VERTEX & ERP
←From VERTEX
↔BOTH WAYS
Order and line data for tax calculation: Product codes, customer location, taxability flags and line amounts flow from commerce into Vertex
Vertex calculates tax by line and jurisdiction, returning rates and amounts back to commerce for display and order capture.
Tax amounts to checkout and invoicing: Calculated tax appears in the checkout summary, is captured on the order record, and flows to the ERP invoice
The tax rate and amount are visible to both the customer and finance teams.
Taxability and exempt-customer rules: Product taxability codes and customer exemption certificates are maintained in the ERP or tax master system, synced into Vertex for rate calculation, and reconciled back against commerce orders for audit.
Rate and rule changes on schedule: Tax rate updates from Vertex are pulled into commerce on a scheduled basis to keep checkout calculations current with jurisdiction changes, preventing mispriced or non-compliant transactions.
Tax lines for invoice and reconciliation: The tax amount and treatment from Vertex flow into the ERP invoice alongside the order lines, enabling finance teams to reconcile tax payable against order activity and close accounts by jurisdiction.
08 · How we build it

How iWeb configures the integration around your business.

Same method on every integration. The decisions come before the code.

  1. 01
    Map product taxability and exemption rules

    iWeb defines which products are taxable, which customers are exempt, and what certificates are required. Those rules are encoded into the integration so checkout uses the correct flags and Vertex calculates from the right starting point.

  2. 02
    Build tax-rate deployment and testing

    iWeb manages Vertex rate-file imports, validates them in a staging environment, and controls the cutover to production so new rates and jurisdictions take effect on schedule without surprises or breakage.

  3. 03
    Handle exemption and refund scenarios

    iWeb builds logic to re-calculate tax on order amendments, refunds and credits so adjustments stay compliant. Exemption certificates are tracked by expiry and applied correctly to new orders from the same customer.

  4. 04
    Monitor tax calculation and reconciliation

    iWeb instruments the tax flow with alerts for rate-import failures, calculation mismatches between Vertex and the ERP, and exceptions in exemption-certificate validation. Finance teams see problems before customers do.

  5. 05
    Audit and report tax by location and rate

    iWeb builds reporting views that tie each order's tax to the jurisdiction, rate type and Vertex calculation. Refunds, adjustments and exempt transactions are tracked separately so finance can reconcile and report by tax authority.

09 · Ownership

Who owns what.

The single most important table in any integration. One system owns each field; everything else reads it.

Data
Source / owner
Maintained by
Notes
DataProduct taxability flags
Source / ownerERP or PIM
Maintained byTax and compliance team with input from merchandising
NotesSynced to commerce and Vertex; never maintained in commerce alone or Vertex alone to avoid drift.
DataCustomer exemption certificates
Source / ownerCommerce platform customer record with ERP customer account
Maintained byCustomer service and finance team
NotesCertificate status, expiry and validation rules are managed centrally; exemption is applied at checkout and reconciled against invoices.
DataTax rates and jurisdiction rules
Source / ownerVertex
Maintained byVertex account team (automatic updates) with business rules defined by finance
NotesRates are imported on schedule; effective dates are controlled by iWeb's deployment process to prevent accidental application before cutover.
DataCalculated tax amount per order
Source / ownerVertex at transaction time
Maintained byVertex integration (real-time calculation)
NotesCaptured on the commerce order, synced to the ERP invoice, and reconciled by finance. Amendments and refunds trigger recalculation.
DataTax lines for invoicing and reconciliation
Source / ownerERP invoice
Maintained byERP (capture from Vertex and order lines)
NotesFinance team reconciles tax by jurisdiction, product and customer type; audit trail links back to Vertex calculation and original order.
DataRate-change test and deployment schedule
Source / owneriWeb integration configuration
Maintained byiWeb and finance team
NotesEnsures new Vertex rates are validated and cutover happens on the agreed effective date; prevents early or late application.
10 · Experienced integrator

Built this before

iWeb has integrated Vertex O Series with commerce and ERP systems across multiple sectors. We understand tax governance, rate-change control, exemption validation and the reconciliation demands that come with scaling across jurisdictions.

iWeb maps product taxability and customer exemption rules from ERP or PIM into Vertex so calculation is consistent at checkout and on the invoice.
iWeb owns rate-import testing and cutover so new Vertex rates apply on schedule and are validated before affecting live orders.
iWeb builds exemption-certificate workflows that validate at order time and expire automatically, so finance never processes non-compliant exemptions.
iWeb instruments tax reconciliation between Vertex, commerce orders and ERP invoices so finance can close accounts with audit-ready certainty.

Enterprise digital commerce specialists since 1995

UK-based, employee-owned team

Adobe Gold Commerce Partner

ERP, PIM and operational integration experience

Build, replatform, rescue and long-term support

Platform-led where appropriate, integration-led across the wider estate

11 · Before launch

What we test before launch.

Every one of these is rehearsed before a customer ever sees the integration.

Verify product taxability codes are consistent between the source system and Vertex, and that changes propagate within acceptable latency.
Test exemption-certificate validation at checkout: valid certificates should suppress tax, expired or invalid ones should apply tax or prompt customer action.
Run sample orders through Vertex and verify calculated tax matches the expected amount for each jurisdiction, product and customer type.
Simulate a Vertex outage and confirm commerce has a safe fallback mechanism and that exceptions are logged and visible to finance.
Validate that refunds, amendments and multi-line orders recalculate tax correctly and that ERP invoices reconcile to Vertex calculations.
Confirm that tax-rate updates from Vertex are imported, validated in staging, and cutover to production on the agreed effective date without early or late application.
Verify audit logs capture Vertex calculation inputs, outputs and timestamps so compliance teams can satisfy regulatory requests and trace errors back to root cause.
12 · Failure points

Common risks and where they bite.

We name these on day one. A risk written down is a risk you can plan around.

Stale taxability codes in commerce

If product taxability is maintained separately in commerce, PIM and ERP, they drift out of sync. An exemption-eligible product gets taxed incorrectly, or a taxable item appears tax-free in some channels. Reconciliation reveals large unaccrued liabilities.

Rate-update deployment missed or delayed

Vertex releases new tax rates for a jurisdiction, but the import process is manual or unmonitored. Orders after the effective date use old rates. Finance discovers non-compliance weeks later during close, forcing retroactive adjustments and audit exposure.

Exemption certificate expiry not tracked

A customer's tax-exempt status is set in the commerce system but never expires or is not re-validated. Months later, they still see tax-free pricing despite their certificate lapsing. The exemption claim becomes invalid and the order is now non-compliant.

Tax amount mismatch between Vertex and invoice

Vertex calculates tax at transaction time, but the amount that flows to the ERP invoice differs due to rounding, multi-entity allocation or refund logic not being wired. Finance reconciliation fails and tax payable is understated.

No rollback or recalculation after rate change

A new tax rate goes live and orders after that point use it, but no process exists to re-calculate or adjust historical orders affected by the retroactive rule change. Customers and finance teams see inconsistent tax for the same product on the same day.

Checkout timeout or fallback on Vertex outage

Vertex is unavailable during peak trading. Commerce does not have a fallback tax mechanism and either fails checkout entirely or uses a default tax percentage. Orders that go through with wrong tax amount cause refund requests and reconciliation chaos.

13 · Where it applies

Relevant services and sectors.

14 · Questions

Common questions about Vertex integrations.

How do we ensure product taxability codes stay in sync across commerce, Vertex and the ERP?

iWeb defines taxability as a PIM or ERP attribute that flows to commerce at product import and to Vertex at order time. Changes to taxability are made once in the source system and propagate through the integration; they are never maintained separately in commerce or Vertex.

What happens to an order if Vertex is unavailable at checkout?

iWeb builds a fallback mechanism: commerce can either queue the order for tax calculation after Vertex recovers, or apply a safe default tax percentage for time-sensitive sales. The fallback is monitored and exceptions are escalated to finance for manual review.

How do tax-exempt customer certificates get validated and applied?

Exemption certificates are stored in the customer record in commerce and/or the ERP. At checkout, the integration verifies the certificate is valid, not expired, and matches the product being purchased. Vertex is told the customer is exempt and does not calculate tax. If the certificate expires, the exemption is automatically removed on the next order.

How do we test a new tax rate before it goes live?

iWeb runs Vertex rate imports into a staging environment where orders are calculated against the new rates. Finance reviews sample orders by jurisdiction and product type to confirm correctness. Only after approval does the new rate file cutover to production on the agreed effective date.

What happens to tax when an order is refunded or amended?

The integration re-calculates tax via Vertex based on the amended line items or refund amount. The tax adjustment flows back to commerce and the ERP so the refund invoice shows the correct tax credit. Rounding and multi-entity allocation rules are applied consistently.

How do we reconcile tax between the commerce order and the ERP invoice?

iWeb creates a reconciliation view that ties each order's tax amount to the Vertex calculation, the ERP invoice line, and the jurisdiction. Finance can filter by location, rate type, customer status and date range to verify no tax is missing or overstated.

Can Vertex handle orders with multiple delivery addresses or tax jurisdictions?

Yes. Vertex can calculate tax per line based on the ship-to address. iWeb ensures each line's location is sent to Vertex and the correct tax rate for that jurisdiction is applied. Multi-line orders may have different tax amounts; the invoice itemizes tax by line so finance can reconcile.

What audit trails do we keep for tax compliance?

iWeb logs each Vertex calculation with the inputs (product, location, customer status), the output (tax rate, amount), and the timestamp. Order and invoice records store the calculated tax. If a rate change or exemption error occurs, the audit trail shows what was applied and when so compliance teams can satisfy regulatory requests.

How often are Vertex tax rates updated and how do we control the cutover?

Vertex publishes new rates as tax rules change in each jurisdiction. iWeb imports them on a scheduled basis (typically weekly or monthly), validates them in staging, and applies them to production on the effective date. Business rules can be configured to delay or prioritize certain jurisdictions if needed.

What happens if a customer's exemption certificate is invalid or expired?

iWeb validates certificates at order time. If a certificate is invalid, expired or missing, the integration either rejects the exemption and applies tax, or flags the order for manual review. The customer is not surprised at checkout with unexpected tax because the certificate status is checked before the order is confirmed.

How do we handle tax for subscription or recurring orders?

Recurring orders are treated as new transactions. Each renewal order flows through Vertex with the current taxability flags, customer status and tax rates. If a customer's exemption expires, the next recurring order will see tax unless the certificate is renewed.

Can we report tax by product, customer and jurisdiction for finance and audit purposes?

Yes. iWeb builds reporting views that segment tax by product category, customer type (exempt vs taxable), jurisdiction and time period. Finance can drill into specific orders to understand why a particular tax amount was applied and trace it back to the Vertex calculation and the ERP invoice.

What happens if a tax rate is applied retroactively by a jurisdiction?

iWeb works with finance and compliance to determine if affected orders need to be recalculated and adjusted. The integration can re-run historical orders through Vertex if needed, generate credit or debit adjustments, and post them to the ERP so all accounts are corrected.

How do we manage tax across multiple legal entities or brands in a single ecommerce platform?

iWeb configures Vertex to apply the correct entity and tax treatment based on the order's invoice destination and the selling entity. Rules are defined in the integration so the right entity is invoiced and the right tax jurisdiction rules apply to each order.

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