Why is my supplier list empty or incomplete?

Has a supplier item been created?

Categorising an account as a "supplier" alone is not enough for the supplier to be included in the purchase overview. They must have at least one supplier item with a price in that price group. See: Create a supplier

Assign supplier items linked to sales or production items to suppliers and remember to enter a valid price.

Has an item group been selected that the supplier does not supply?

If a specific item group is selected on the right-hand side of the purchasing overview, only those suppliers who can deliver items from this group are listed.

Left-click on the top empty line of the list of item groups to show all items and all suppliers.

Is the "Main suppliers only" field selected, but there are no main suppliers?

To limit the supplier selection for better readability, suppliers can be labelled as main suppliers. The list can be filtered accordingly.

Left-click on  Main suppliers to deactivate the filter and expand the selection again.