On 12 May 2021, the Federal Council decided in its meeting not to exempt Swiss Guards from the military service tax for the duration of their deployment in Vatican City.
The Federal Council thus does not follow the draft legislation of the National Council's Security Policy Committee (SiK-N). An exemption would both disregard the principle of equal treatment of all substitutes and violate the prohibition of discrimination against other denominations. Finally, the Swiss Guards are not considered military, but police service for a foreign state, which means that they do not perform an indispensable activity for the benefit of the Swiss population.
The Federal Council's statement is available here, the entire media release is available here.