Ok. So think about what that actually means. You get a payment from the government for $1000 once a month. Then they take $2000 in taxes from your paycheck once a month. Net, you paid $1000 in taxes. For you, it is indistinghuisable from a system where you paid $1000 less in taxes because of lower rates. UBI functions like the standard deduction for your purposes, except insofar as it is refundable if your income and thus taxes owed drops below the UBI level, whereas a traditional refundable tax credit is refundable only after the return is filed, once per year.
You can relabel the account balances however you want, but the underlying economic reality is the same for people earning income taxable above the UBI amount. You are paying more to the government than you are receiving. For people near or right on that level, they simply have an accelerated refund schedule.
