1) If their check is returned from your bank.2) If deadline is missed, charge late fee and check bounce penalty. But state this to tenant:"I will charge you these fees for now. But I can refund these fees if you can provide concrete proof from your banks that these funds were indeed available on XX date YY year when the check was processed, and or provide concrete proof that it was landlord's bank's mistake (like they often say). Before these evidences are given, your new rent for this month is increased to original rent + late fee + penalty. No partial payment is accepted. It is tenant's responsibility to ensure full availability of fundings and delivery of payment.3) If deadline is not yet missed, warn them that a bounced check fee is now added to this month's rent. for example, original rent is 1000, now new rent is 1035 (with a bounced check fee added). If **full** payment is not received by 10th day of the month, a suit will be filed in district court for delinquency. Same as 2), if proofs can be provided later, such lawsuit can be dismissed, and fees can be refunded.In my experience, I haven't met a tenant who can provide a proof that it's my bank's mistake. A bounced check has 99% chance that their money is not in their account.So, go ahead and charge fees. Leave the burden of proof to themselves.Not you.（sunskitehomes）Bottom line: It is tenant's responsibility to pay on time.If somebody else made a mistake, sure refund the late fee. But in most cases, they are lying.However, if you go to their bank and obtain a proof of insufficient fund yourself, then you could require money order or cashier's check onwards without exceptions.
