This is the date of the purchase invoice. The due date of the purchase invoice is calculated based on this date and the number of days specified in the applicable payment condition.

The posting date is the date assigned to the journal entry of the purchase invoice lines.

This field is used in your financial application as a payment reference. For instance, it may the debtor number your supplier uses for your company, and the number stated on the purchase invoice you have received from your supplier.

Note: When the purchase invoice is saved, Isah checks for the combination of creditor code and reference. This is done to avoid duplicate entries of invoices you have received from your suppliers. If the combination already exists, the following message is displayed: 'Creditor/reference combination already exists. Continue anyway?'

Note: If you are using Isah Finance, the Reference field is a required field, as the reference is required for the purchase day books in Isah Finance.

This field shows how the purchase invoice was registered:

• Manually: The purchase invoice was added to the Purchase invoices form using CTRL+N.
• Electronically: The purchase invoice was received from the supplier by electronic means and was automatically imported into Isah. Even if the purchase invoice is changed manually at a later stage, the value of this field will remain 'Electronically'.

This is the currency used to express the sums on the purchase invoice. The currency applies to both the purchase invoice header and the invoice lines. In Isah, the invoice sum is automatically converted into the local currency.

You can change this field as long as no purchase invoice lines are present. To change this field when purchase invoice lines already exist, you need to delete these lines first. Purchase invoices and purchase invoice lines can be changed until the invoice has been processed permanently.

Copy the value from the purchase invoice received to this field. The invoice sum is the total invoice sum, including VAT.

As soon as you save the purchase invoice, the VAT sum is calculated automatically. You can change the VAT sum and the VAT code, however, by clicking the VAT sums button.

Note: If only one VAT code is applicable to the purchase invoice, and you change the invoice sum, you will be asked whether the VAT sum is to be recalculated. If you choose 'Yes', the VAT is recalculated and modified as soon as you save the purchase invoice.

By default, one VAT line is created when the purchase invoice header is saved. This VAT line is based on the VAT code specified for this creditor on the Suppliers form (Financial tab). You can change the VAT sum and the VAT code, however, by clicking the VAT sums button.

This field contains the VAT sum on the total invoice sum. This VAT sum is calculated based on the VAT code specified for this creditor on the Financial tab of the Suppliers form. You can change the VAT sum and the VAT code, however, by clicking the VAT sums button.

This field contains the net invoice sum. This is the total invoice sum excluding VAT.

Purchase invoices cannot be processed unless they have the right authorization. The authorizations correspond to the possible processes. The field has three possible settings:

Do not process:	The purchase invoice has not yet been released for processing, or has already been permanently processed.
Process provisionally:	Use this authorization to calculate the VAT receivable for a VAT return. Using this authorization, you can provisionally process an invoice. This does not require the lines to have been entered yet. The final correction will take place at the time the invoice is permanently processed.
Process permanently	This option means you are authorizing the purchase invoice for permanent processing. Purchase invoices can only be authorized for permanent processing if: All purchase invoice lines have been entered and authorized, AND The invoice sum excluding VAT in the purchase invoice header matches the sum of all underlying purchase invoice lines, or (if you are using allowed variances) the sum that is within the variance margins.

If this check box is selected, the purchase invoice has been processed provisionally. You will also see the date on which this was done.

If this check box is selected, the purchase invoice has been processed permanently. You will also see the date on which this was done.

You can change this field as long as no purchase invoice lines are present. To change this field when purchase invoice lines already exist, you need to delete these lines first. Purchase invoices and purchase invoice lines can be changed until the invoice has been processed permanently.

This is the creditor to whom you must pay the purchase invoice. The creditor does not have to be the same as the supplier.

The due date of the purchase invoice is automatically calculated based on the number of days specified in the payment condition stated by the supplier, starting from the reference date of the purchase invoice. You can change the due date, if required.