How to handle customs in purchasing process, so that the customs duty would be calculated to item cost?
Note that we use Lot actual costing in BAAN IV c4.

thanks a lot!

A way to introduce a surcharge to item price is to introduce a line in the PO with no quantity, no price but only amount, for the same item purchased.

I have not tested this with lot items but maybe this can work for you.

Good luck and let us know.

But for customs, dont need to print in PO and should not be paid to the vendor.
there should be an tax payable like account to take the amount instead of AP.

and customs are actual price based.
should be a "surcharg" to the actual purchasing price.

Indeed they are, though there is a distance component to the taxes, too. See import courses (https://w2c.ca/en/training/customized-customs-coaching/) for more details.