Any penalty for claiming too many allowances?

I recieved a little over 500 dollar refund last year from federal. My taxable income (line 43 of IRS 1040) was 14,678. According to the kiplinger tax allowance estimator calculator, it suggests that I may take 2 more allowances everything else being unchanged from last year. Is there any recourse if I take several additional allowances on my W4 and end up owing like 500-1000 at tax time vs. Uncle Sam owing me as long as I have the money to pay the bill by the April deadline? I'd like to start borrowing money interest free from Uncle Sam for once.

TimH,

You are probably safe to take the additional allowances.

Here are the 3 safe harbors for paying estimated tax or needing additional withholding:
1) Will you owe $1,000 or more for 2006 (line 75 on the 2005 return), after subtracting withholding, credits and estimated payments? No? you can wait to pay this additional tax when you file your return.

2) Will your withholding plus credits plus estimated payments be at least 90% of your 2006 tax owed (line 46 on 2005 return)? Yes? you can wait to pay this additional tax when you file your return.

3) Will your withholding plus credits plus estimated payments be at least the amount of your 2005 tax (line 46 on 2005 return)? Yes? You can wait to pay the additional tax whenyou file your retrun.

Thank you Clyde. I was hoping on of the "seasoned" veterans would answer this question for me. I will review the criteria to ensure I qualify, but I will definitely take advantage of the extra pay per month. -Tim