Real estate taxes, sometimes referred to as property taxes, are claimed in the tax year they are actually paid. It does not matter what year is paid *for*. So if you paid $90K in property taxes in 2020, that's what you're report on your 2020 tax return. If they IRS want's any explanation, then they will specifically ask you for it. Including information with your return that the IRS does not require or has not specifically asked for, generally will tend to hold up the processing of your return moreso than if you just wait until the IRS asks you for more information or clarification.
If the IRS conducts an audit, then the only reason that would be of any concern to you would be if you're trying to hide something.... and you're not doing that.
