<prompt> Human: Our home was appraised at 230k in 2016 and at 116k in 2017 which is of course a mistake. We got a letter explaining we had overplayed our escrow by about 4k and the bank wrote me a check for that amount. I did the math and the 4k is the difference between our tax rate at 230k versus 116k. The letter also stated our new monthly payment is lower as well due to our lower required escrow payments.I am scared as hell to cash that check because I feel like the county will realize their mistake and come asking for the money later on. I am also not wanting to start paying less each month to suddenly be charged a few grand come January 2019. We are now about the get our 2018 tax appraisal document...no clue what itll hold. My biggest question is, once the county has assessed my property and a tax year has come and gone, can they retroactively charge me taxes for their 2017 tax clerical error? Also, would you let the county know their error? Would you cash the check?  <response>: You should definitely cash the check. Its your money, it was just originally set aside to pay property taxes. If you think theres a chance of the county revising your property tax up for 2017 after youve already made the payment? then dont spend the 4k.If your escrow account is eventually short on a future tax payment which seems very likely in the next year or two then you will likely have to either pay more per month or make a lump sum payment and also pay a bit more per month. Neither of these is a really big deal, assuming you save the 4k you just got, since that will likely be more or less the amount of the future shortage.As to whether they can retroactively charge you taxes, you might want to ask rlegaladvice. 