When importing a purchase invoice, Isah checks whether the purchase invoice already exists by checking for the presence of the combination of the supplier's invoice number and the supplier's SCSN ID. If the combination already exists, a message will be displayed and the import of the purchase invoice will be aborted.

If the invoice message contains an SCSN code for the supplier, but Isah cannot find this code for any supplier in Isah, Isah will abort the import and display an error message.

If the invoice message contains an SCSN code for the supplier, and Isah finds this code for multiple suppliers in Isah, Isah will abort the import and display an error message.

Your own company is registered as customer 99999. The debtor of this 'customer' can be this same customer 99999, but it can also be another company, for example if your company is part of a holding. Isah checks whether the SCSN code of the company that is registered as a debtor for customer 99999 is the same as the SCSN code of the 'Buyer' in the invoice message. If it is not, Isah will abort the import and display an error message.

• If a creditor has been specified in the supplier settings in Isah that differs from the supplier, the message should include a 'Payee'. If these creditor details are missing in the message, Isah will abort the import and display an error message.
• If a creditor has been specified in the supplier details in Isah, then the company specified as a creditor must have an SCSN code. If this code is missing, Isah will abort the import and display an error message.
• If the invoice message contains a creditor (Payee) that differs from the creditor specified in the supplier details in Isah, then the SCSN codes of these two parties must match. If it is not, Isah will abort the import and display an error message.

The invoice type (InvoiceTypeCode) in the message must be '380'. If the invoice type is not '380', Isah will abort the import and report the problem.

• If the message does not contain any data enabling Isah to identify the corresponding purchase order, Isah will abort the import and display a message. These identifying data are the data shown in the OrderReference section of the message; this section must at least list one ID (purchase order number) or SalesOrderID (supplier's order reference).
• If a purchase order number (Purchase order reference>OrderReference>ID) has been filled in, Isah will check the message for the SCSN code of the supplier. Isah will then search for the combination of 'Purchase order number + Supplier SCSN code' in the Isah details. If it is not, Isah will abort the import and display an error message.
• If the purchase order number (Purchase order reference>OrderReference>ID) in the message is empty, but the sales order reference (Sales order reference>OrderReference>SalesOrderID) is filled in, Isah will compare this reference with the value of the Order reference field (PurchaseDocument.VendRequisitionRef) in Isah. Isah will then look up the SCSN code of the supplier and check whether the combination of 'Order reference + Supplier SCSN code' exists in Isah. If it is not, Isah will abort the import and display an error message. Isah will also abort the import if more than one purchase order matches the data.
• If both the purchase order number and the sales order reference have been filled in, Isah will check the purchase order number against the purchase order number in Isah (PurchaseDocument.PurOrdNr), and the sales order reference against the order reference in Isah (PurchaseDocument.VendRequisitionRef). If the purchase order number matches, but the order reference does not, Isah will log a warning, but it will continue the import process.

If Isah has been able to link the purchase invoice to a purchase order, Isah will check the Type field (PurchaseDocument.PurRequisitionType) to see whether it is a purchase order for the sale of parts. If it concerns equipment or external operations, the import will be aborted and a message will be displayed.

The message can have two currency codes:

• Invoice currency code (DocumentCurrencyCode), which applies to the invoice
• VAT accounting currency code (TaxCurrencyCode), which applies to the VAT.

If these two fields in the message have two different currency codes, Isah will abort the import and log an error message.

Isah logs an error and aborts the import if there are no known data about the part lines. In this context, the following pieces of information are important:

• In Isah:
  • the purchase order line (PurDocPartLine.PDPartLineNr)
  • the part specified on that purchase order line (PurDocPartLine.PartCode)
• In the message:
  • the 'Referenced purchase order line reference', which you can find in the message under InvoiceLine>OrderLineReference>Line ID; this is the actual purchase order line
  • the 'Item buyer's identifier', which you can find in the message under InvoiceLine>Item>BuyersItemIdentification>ID; this is the identification of the part on the purchase order line.

The import process will be aborted and an error message will be displayed if:

• the message does not contain a purchase order line or part
• the message does contain a purchase order line, but this line does not exist on the purchase order in Isah
• the message does not have a purchase order line, but does have a part, and this part does not match any of the parts on the purchase order in Isah
• the message does have a purchase order line and a part, but the part does not match the part on the purchase order in Isah.

When importing an order message, Isah checks whether the message complies with the SCSN standard. One of the requirements is that all fields that are mandatory under the standard must have been filled in. For instance, a purchasing party and a selling party must be present, at least one order line must be included, and the participating companies must have an SCSN code.

Any problems are displayed on the Electronic messages form. Once they have been solved, you can import the message.