Rules for Invoice Exports

The Invoice Export hook fires just before an invoice is sent to an external system — typically an accounting platform like QuickBooks or NetSuite, or an EDI partner. Like Shipment Notification, this hook exposes both the invoice and the parent order, so you can use order context to shape the invoice.

These rules are about formatting and routing — making sure the invoice has the right structure, codes, and metadata for the destination system.

Add accounting GL codes

rule "Set GL codes by category"
  when
    order.custom.tier is "vip"
  then
    set invoice.custom.gl_revenue_code to "4100"
    set invoice.custom.gl_cost_code to "5100"
  end

  when
    order.custom.tier is "wholesale"
  then
    set invoice.custom.gl_revenue_code to "4200"
    set invoice.custom.gl_cost_code to "5200"
  end

  when
    order.custom.tier is "standard" or order.custom.tier is blank
  then
    set invoice.custom.gl_revenue_code to "4000"
    set invoice.custom.gl_cost_code to "5000"
  end
end

Different customer tiers map to different general-ledger accounts. Setting them at export time means your accounting system files the revenue under the right account automatically.

Tag invoices for region-specific tax rules

rule "EU tax flag"
  when
    order.shipping_address.country is "DE"
    or order.shipping_address.country is "FR"
    or order.shipping_address.country is "IT"
    or order.shipping_address.country is "ES"
    or order.shipping_address.country is "NL"
  then
    set invoice.custom.tax_jurisdiction to "EU"
    set invoice.custom.requires_vat to true
  end

  when
    order.shipping_address.country is "GB"
  then
    set invoice.custom.tax_jurisdiction to "UK"
    set invoice.custom.requires_vat to true
  end
end

Different jurisdictions need different tax handling — flag the invoice so the accounting system applies the right rules.

Suppress invoices for test orders

rule "Don't export test invoices"
  when
    order.notes contains "TEST"
    or order.custom.tag is "test"
  then
    reject invoice
  end
end

Test orders shouldn’t generate accounting records. Rejecting the invoice in this hook prevents the export — the invoice still exists in DropStream, but doesn’t reach the accounting system.

Add customer reference

rule "Add customer reference"
  when
    order.external_customer_id is_not blank
  then
    set invoice.custom.customer_reference to order.external_customer_id
    set invoice.custom.customer_email to order.customer_email
  end
end

Many accounting systems need a customer ID for matching. Pull it from the order onto the invoice.

Calculate and set totals

rule "Set invoice totals from order"
  set invoice.subtotal to order.subtotal
  set invoice.shipping_amount to order.shipping_amount
  set invoice.tax_amount to order.tax_amount
  set invoice.total to order.subtotal + order.shipping_amount + order.tax_amount
end

If your invoice export requires explicit totals separate from the order’s, compute and assign them. Note: this is straightforward when DropStream’s invoice already reflects the order; use it when transformations elsewhere have changed the values.

Add custom fields for ERP integration

rule "Add NetSuite custom fields"
  set invoice.custom.netsuite_class to order.shipping_address.country
  set invoice.custom.netsuite_department to order.custom.tier

  when order.custom.tag is "wholesale" then
    set invoice.custom.netsuite_subsidiary to "Wholesale Division"
  end

  when order.custom.tag is "retail" then
    set invoice.custom.netsuite_subsidiary to "Retail Division"
  end
end

When the destination ERP needs custom fields beyond the standard invoice schema, populate them in this hook from order data.

Format invoice number for external system

rule "Format invoice number"
  set invoice.custom.external_number to
    "DS-" & order.id & "-" & invoice.id
end

Some systems require specific invoice number formats. Compute and set the formatted string at export time.

Fail if required custom field missing

rule "Fail invoices without GL codes"
  when
    invoice.custom.gl_revenue_code is blank
  then
    fail invoice with "Invoice for order " & order.id & " has no GL revenue code; check tier rules"
  end
end

Defensive: catch invoices missing critical accounting metadata before they reach the destination system. Failing surfaces the issue immediately rather than letting bad data flow downstream.

Tips

• You can read both records. Use invoice.X for invoice-specific fields (GL codes, formatting, totals); use order.X for context (tier, region, customer details, tags from Order Import rules).
• Set the custom fields the destination system needs. Most accounting integrations expect specific fields — know what your destination needs and populate them here. The values often come from order tags or categories that earlier rules already set.
• Reject is your “skip export” switch. Rejecting an invoice in this hook prevents the export but doesn’t delete the invoice from DropStream. It stays available for reference and reporting.
• Order Import + Invoice Export are a pipeline. Rules at the Order Import hook tag and categorize orders; rules here read those tags and translate them into invoice fields. Keep the categorization logic at Order Import and the formatting logic here — that separation makes both sets easier to maintain.