Overall, estimated taxes are estimates calculated based on your income. Depending on how much you pay in quarterly estimated payments each quarter, you may owe some additional money in taxes at the end of tax season. You could also get money back at the end of tax season! Both circumstances are equally okay and to be expected.
It is entirely up to you if you want to pay more or less than the quarterly estimate Heard has calculated for you. If you feel like you may have some additional income not reflected in Heard and/or you want to pay a little extra to cover your bases, feel free to round up our estimate when you pay! If you feel that the estimate is higher than what you anticipated owing in taxes this year, you may want to lower your estimate slightly. This is perfectly reasonable and is not cause for concern.
The main factor we'd like to remind you of is that if you do underpay or skip payments throughout the current tax year, you could be subject to an underpayment penalty and/or interest that you'd be responsible for paying. The best way to avoid such fees are to pay either 90% of this year's tax liability or 100% of prior year's tax liability.