I used an angle grinder to cut a slot in the top of a mailbox just wide enough to slide money into. Do not put a change container on the stand, when I did that people would put their cash in it instead of the lock box. People will learn to come with exact change next time.Bob.

Just the other day a friend shared about a sign she saw at a self-service market. "If you aren't honest, don't shop here!"

Also, think about pricing in easily counted amounts and even dollars, 50¢ instead of 35 or 40, if you expect folks to have exact change.

Never leave the box locked at night. At the end of the day take out the money and leave the box open. If someone comes at night to steal money they will see the open box and leave. If the empty box is locked they will bust it open see its empty and leave... Bob.

You could but a metal box and use a metal cutting blade in a jigsaw to cut out a slot (drill a pilot hole at each end first to start the blade). Or do a search on eBay for "drop box" or "suggestion box". I found some nice lockable boxes for around $10 to use without going through the hassle.