An earlier post has described the Lausanne Handling Charge System of dealing with international unpaid and underpaid mail in effect on January 1, 1976 : International Taxation of Unpaid and Underpaid Mail: 1976 Lausanne Handling Charge System
This post shows how the British Post Office applied the Lausanne system in the late 1970s and 1980s.
The Lausanne System
The Lausanne system required the county of origin to mark the letter with a T stamp along with a fraction in which the numerator was single the amount of the underpayment and the denominator was the country of origin's international letter rate.
The country of delivery would then multiply the tax fraction by its international letter rate to calculate the charge and add a handling fee.
11p Handling Fee
Bridgewater to Birmingham, February 24, 1976
20 cent international letter rate
Short paid 4 cents : Canadian Taxe fraction 4/20
British handstamp "13P TO PAY"
Canadian T fraction
Numerator 4 ( 4 cents deficiency)
Denominator 20 ( 20 cent international letter rate
British Calculation
The British international letter rate was 10p.
Postage Due = (4/20 x 10p) + 11p= 13p
15p Handling Fee
Edmonton to Tovil, Maidstone, April 2?, 1979
35 cents international letter rate
Shortpaid 18 cents : Canadian Taxe fraction 18/35
British handstamp "20p TO PAY'
Canadian T fraction
Numerator 18 (18 cents deficiency)
Denominator 35 ( 35 cents international letter rate
British Calculation
The British international letter rate was 10 1/2p.
Postage Due = (18/35 x 101/2p) + 15p = 20p
20p Handling Fee
Calgary to Bury St. Edmunds, England, January 24, 1983
64 cents international letter rate
Shortpaid 4 cents : Canadian Taxe fraction 4/64
British handstamp : "21p TO PAY"
Canadian T fraction
Numerator 18 (18 cents deficiency)
Denominator 35 ( 35 cents international letter rate
British Calculation
The British international letter rate was 19 1/2 p.
Postage Due = (4/64 x 19 1/2 p) + 20p = 21p
Reference
Furfie, Michael, British Civilian Postage Rates of the 20th Century, Published by Michael Furfie, Ashford, England, 2000
