3 Sep 1989 to 1 Jan 1991
US foreign surface letter rate 40 c (3 Apr 1988-2 Feb 1991)
Swedish standard total fee for incoming due items: 500 öre (4 Sep 1989-1 Jan 1991
US handstamp shows amount missing in US cents and US surface letter rate.
In Sweden the indicated fraction was ingnored and instead a standard fee of 500 öre was charged normally paid by affixing stamps on an advice card sent along with item by the Swedish post office. Items handed out at the window or by rural carriers may have the amount due affixed on the item.

Incorrectly treated postcard with 25 c. Correct rate 28 cent. The US due handstamp indicates 3 c shortpaid but incorrectly 28 instead of 40 as foreign letter rate. No indication of due in Sweden. 500 öre should have ben charged.