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First off, I'm not working as a contractor now, so this doesn't really affect me, but I'm wondering if it would make sense to have such a policy outlined in your contracts, but be generous and specific in enforcing it. For example, mark clearly on the invoice those times where you choose to waive it: family emergency, not wanting to upset a really good client, etc., but if you have a client with a history of late payments, or repeated late cancellations, you are within your rights to enforce your policy. Most of the time, you come off looking like the 'good guy,' or 'hero,' or whatever, but your butt remains covered when you need it. Thoughts?