Claim one or two allowances?

Normally if you claim 2 allowances all year you will be close to even money at filing time, usually within $150 either way. Since you have been claiming 0 allowances so far, you will still be looking at a refund at filing time next year.

Starting next January, cut that to 1 allowance if you absolutely don't want to owe a small amount when you file in 2019. If you are OK with possibly owing up to $150 or so, stick with 2 allowances.

You can't have it both ways.

For a single person with no dependents, 0 will get you a refund. Claiming 1 will get you closer to break-even, but probably get you a small refund. Claiming more than 1 will most likely leave you owing taxes.

If you want to get a refund and still get more take-home pay, you can change to 1 allowance. This will give you roughly $40 more per month take-home but reduce your refund by that amount at the same time.

2 allowances will cause you to break even or owe a bit.

there is a W-4 calculator at www.irs.gov and I think you will find single 2 is appropriate for you

You better just claim one, because if you claim 2, you may have to pay in taxes at the end of the year !

One

With 2, you could end up owing, or might receive a small refund. Claim 1 to be sure not to owe, to get a refund.

Do not take more than one or you may have to pay tax.

If you want to get money back when you file taxes, file 0. If you want to be as close as you can to what you will really own, claim one. If you want to pay, claim more than one.

If you answer the questions correctly on the W4 worksheet, they should be taking out just about what they should so that you don't have a huge refund (more in your paycheck) or have to pay a huge deficit (unexpected expense) when it comes to tax time. Single, no dependents seems to indicate that you should claim 2 allowances.