Some time ago when I knew about an increase in the price of 1st and 2nd class stamps I bought several hundred stamps. I know that I won't want to use these before 31/1/23 so I sent off 100 1st and 100 2nd class stamps for replacement with bar coded ones.
As the total value of these stamps is £163 I thought it would be nice to have proof of posting so I went to the post offcie. Unfortunately the queue there stretched out of the door so I just put the letter in the box.
The replacement stamps arrived today and the postman rang the bell and handed me the envelope saying that he had to do this. The sheets of 100 bar coded stamps are much larger than than the previous ones.