system of checks and balances
Refers to a totally-legal but still-somewhat-devious practice of writing personal checks for comparatively-minuscule bills --- like maybe just two or three bucks for a bag of fresh vegetables from a roadside farm-stand --- instead of paying them in cash, and then secretly hoping that the checks’ recipients will not want to bother going to the extra effort of cashing said “tiny” checks, and thus your bank-account’s “balance” will be unaffected by your purchases.
Practicing the “system of checks and balances” can have varying degrees of success, depending on various factors, such as how strapped your checks’ recipients are for cash, how accustomed they are to cashing/depositing checks, or how willing/able they are to accept checks, especially for such paltry amounts (here’s where paying with checks at an unattended “drop the money in the slot” or “place the money in the cup/jar” merchandise-stand can be a good idea, since there will be nobody there to balk at your paying with a check). Extra points if you “embellish” the checks with flowery praising messages about how wonderful the sellers’ merchandise/service is, since it may stroke the people’s ego so much that they will prefer to “frame it rather than cash it” (again, especially since the check is for such a small amount, and so its value might likely not mean all that much to the person’s overall budget) when deciding what to do with your checks.