This simple idea is called "error trapping".
Other software processes will check that the cumulative data you have entered makes some kind of sense by testing the data against norms.
It is good to know that such simple ideas can help prevent fraud, or at least detect it quite quickly, as this story illustrates.
A father-of-two has admitted fraudulently claiming almost £80,000 in benefits for 36 children.
Irvin Fraser, 30, claimed child tax credits over three years from two addresses in Aberdeen.
- Fraser said: "I was claiming child tax credit for my son and just added another name by chance.
Then the finger is pointed.
- "They never asked for any documents. It went on for two years and I got away with it. "I couldn't understand why they did not pick up on it. How could someone claim to have so many children but not be old enough to have them?"
But seriously, how many others have done this and just not been prosecuted? Is this why online claims were stopped? Have the software providers been asked why their system didn't do simple checks? Or were they simply given the wrong specification, and provided what was asked for?
At least the national ID scheme (partially deceased) won't have these sort of stupid mistakes in the data base will it?