Do you love doing your taxes? Me too. And the day we dread -- April 16 -- is not that far away, when we'll no longer be so focused on our taxes, and we'll have to wait another 11 to 12 months before preparing our next returns. It's awful, isn't it?

At least it's not here yet. We can still thrill in the collection of our financial documents, and delight in filling out tax schedules. And we can whip out our checkbooks with glee, if we need to send Uncle Sam some money. So far, so good. But some of us may be leaving our checkbooks behind, planning to pay with our credit cards.

That can be profitable -- if we're smart about it. For example, you might charge your taxes on Citigroup's (NYSE: C) Citi CashReturns credit card, which was recently offering 5% cash back for three months, with no limit to the cash you can earn. (Check out this card comparison site for more options.) 

Earning 5% can get you $250 on a $5,000 tax bill. But be careful -- there's a catch. When we pay our taxes with plastic, we do so through third-party service providers, and they typically charge a 2.49% fee. That's not chicken feed. If you owe $5,000, for example, you'll fork over an extra $125 -- just for the privilege of not writing a check. Is that really worth it?

If you make $250 via your credit card cash-back program and pay the $125, you'll still come out ahead. But if your cash back is just 1%, giving you $50, you'll end up in the red. Better to opt for a dollar or so in postage.

And don't fall for the rewards trap, either -- you'll have to earn more than 2.49% as your reward to make charging worthwhile. American Express' (NYSE: AXP) advice, to use Membership Rewards to pay the tax fee, is also dubious. According to Bill Hardekopf, CEO of LowCards.com, doing that will use up almost as many points as two free plane tickets.

Still, I recommend a judicious use of cash-back credit cards for expenses other than taxes. I've earned hundreds of dollars that way, and counting. My Discover (NYSE: DFS) card, for example, pays me 5% back on gas. JPMorgan Chase (NYSE: JPM) offers a card that pays you 3% in categories where you spend the most.

Learn more about how to make the most of your credit in our Credit Center.

Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article. JPMorgan Chase is a Motley Fool Income Investor recommendation. Discover Financial Services is an Inside Value recommendation. Try our investing services free for 30 days. The Motley Fool is Fools writing for Fools.