Save those unused envelopes with windows that sometimes come with bills. You can use them for your own personal mail by writing the address on a 3X3 post-it note (under or over the sticky area) and placing it in the envelope so the address is showing in the window. It may take a trial run but once you figure out how it's done, you'll never throw away an unused window envelope again.
I am glad someone mentioned the barcode. I used the wrong envelope to pay one of my bills and to this day I have a check that never reached it's destination and I have no idea where it got to. It was never cashed. I realized I had used the wrong envelope when I went to pay another bill later that week and I found the original envelope that I should have used.
By
08/08/2008
This is a good way to save on envelopes, BUT, if you notice, there is usually a barcode on the envelope somewhere. That barcode is for the company who sent it and usually goes back to them when "swiped". I did this for a year until I found out, some of my payments were going other places. I would not use the envelopes that have the barcode on them. Be careful!