1 May 1967 - 30 June 1971
US foreign surface letter rate 13 c
Swedish foreign surface letter rate 70 öre
US handstamp shows amount to pay in US cents (normally double deficiency) and US surface letter rate.
In Sweden the indicated fraction multiplied by 70 and rounded up to nearest 5 öre was normally paid by affixing stamps on the item.
Air mail postal
card with 8 cent. Correct rate 13 cent. Shortpaid 5 cent. US due handstamp
indicates double deficiency 2x5=10 cent and surface letter rate 13 cent.
Amount due in Sweden; 10/13 multiplied by Swedish foreign rate 70 öre
= 53.85 öre rounded up to 55 öre. Stamps should normally have
been affixed on the on the item but the amount has probably been ignored
or the stamps affixed elswhere.