While the federal government debates regulations to better warn consumers of cellphone overage charges, there are plenty of steps those subscribers can take now to better keep bills under control.

The Federal Communications Commission has invited consumers to share comments on bill shock -- the often exorbitant charges for exceeding the voice, text and data limits on cellphone plans -- through late June. The agency is considering a regulation that would require carriers to warn consumers with a free text message when they are about to incur overage or roaming charges. A similar law in Europe requires such notification, and also allows consumers to cut off service instead of going over.

Although there have been several high-profile U.S. cases with bills in the thousands and tens of thousands of dollars for texting and data use, it s more common for users to go slightly over. The average overage is $2.60 per month, reports market research firm Nielsen. Once charged, such fees are tough to reverse because they are usually terms consumers agreed to when subscribing, says Bob Sullivan, the author of Stop Getting Ripped Off. Carriers tend to hold the line on these, he says.

It s only going to take one payment-shock bill for people to make a change, says Todd Mark, the vice president of education for Consumer Credit Counseling Services of Greater Dallas. If you d rather avoid the experience completely, here s how to overage-proof service:

Calculate overage charges

Even if you go over, you have to look at how much you go over, says Maggie Reardon, a spokeswoman with electronics-review site CNET.com. A small overage may not justify switching to a more expensive plan. At T-Mobile, for example, consumers on the 500-minute Even More plan ($40 a month) pay 45 cents a minute in overages. They d need to talk for more than 22 minutes to justify trading up to the next-biggest 1,000-minute, $50 plan.

Check in online

All the major carriers allow subscribers to log in and see an up-to-the-minute assessment of their plan use for that statement period. It s healthy to check your status at least once a week, Sullivan says.

Call for balances

A few carriers let customers check in from anywhere. Verizon, for example, lets users call #MIN for free updates on minutes used. T-Mobile subscribers can call *611 and say message use or minutes for balances, or dial #MSG# or #MIN# directly. Review carriers sites for more details about how to check in while on the go.

Consumers who find themselves dangerously close to going beyond their plan limits can make an impromptu switch to a more generous plan -- without resetting the clock on their contract. Customer service reps will even make it apply retroactively if you ask nicely, Sullivan says. Change back to the original plan for the next billing period.

Re-assess your plan

Cellphone minutes aren t easy to budget as you go, Mark says. Look at past bills to determine appropriate levels of minutes, texts and data needed. Then use a comparison site like BillShrink.com to compare available options.

Infrequent cellphone users and those on a tight budget may want to consider switching to prepaid service. There s no contract, and users pay as they go -- providing a built-in limit, he says. On the other end of the spectrum, heavy talkers, texters and web surfers should look to unlimited plans. Those offerings can be budget-friendly, too, with offerings as cheap as $40 a month.

Nix auto bill-pay

Don t agree to let the carrier pull cash from your checking account each month. There s something to be said for people who have to look at their bills, says Reardon. Users who opt for auto-pay are less likely to notice small, regular overages from having the wrong plan -- and could find their checking accounts out a substantial amount of money should a larger problem like international roaming or a data mishap occur.

Set usage controls

For $5 a month, Verizon and AT&T let users set alerts when text and voice allowances have been reached, restrict services during set times or days, and require users to dial numbers twice to make a call when roaming. Consumers can also cut off services that cost extra, such as 411 calls and ringtone downloads.

Use smartphone caution

Many carriers require unlimited data plans for data-hungry phones. If it doesn t, read expert reviews and talk to your carrier about how much data the phone uses for basic tasks like checking email, Reardon says. Charges can add up fast. BlackBerry handsets tend to be most efficient, she says.