How did GPO staff know foreign stamps were demonetized?

[Ozdoba]

Hello from Switzerland

I have a letter that was sent from St. Gallen/Switzerland to the UK in late 1924.

The stamp was a 30 Rappen from the special issue "50 Years UPU" (Zumstein #168).
This stamp was issued on October 9 and only valid until November 30.
As it was stamped in St. Gallen on December 3, it was already demonetized when the letter entered the UK; therefore, it was considered not franked and the receiver was charged 5p "Postage Due."
My question: Considering the number of letters that arrived from all parts of the world, how did the GPO inform its employees about demonetization of foreign stamps? Did they have posters hanging in the office showing such stamps, did they have daily/weekly briefings?

Thank you in advance for any information
Chris

[Galveston]

Hello - I do not follow this area and I’m sure there are others that could easily answer this , but here are some things I have found that may be of interest. Unfortunately I did not see an answer to your question…..

https://www.upu.int/UPU/media/upu/file ... ionsEn.pdf

https://www.upu.int/en/Universal-Posta ... PU/History

https://www.upu.int/en/Universal-Posta ... t-UPU/Acts

Good luck - Regards, William

[Ozdoba]

Thank you, William

interesting information! Here's another one (slightly off-topic ...):
The UPU was founded (and still has its headquarters) in my hometown, Bern.
Near to the "Bundeshaus" (our parliament building) is a small park where you find the UPU monument:

Kind regards
Chris

[Galveston]

Very nice - thank you. Please report back when you find your answer. Good question!

Rgds - William

[admin]

The general answer is that they didn't -- the originating country was supposed to mark the letter, and the destination country take their word for it.

The procedure was for the office of posting to draw a box around the stamp without cancelling it to indicate that it was invalid, and put a "Taxe" mark on the letter. Here the Swiss marked the stamp as invalid and stamped it with the "T" in circle.

[Ozdoba]

Thank you - that settles it.

Chris