Mel, that probably should be dictated by your own bank's credit policy, and based on management's risk tolerances. It could also be identified on the amount and type of credit requested.
I've seen a few banks with "similar credit history to the amount, terms and conditions requested." (meaning they do not want to be the first on the block to lend to a person.)
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Integrity. With it, nothing else matters. Without it, nothing else matters.