(MONEY Magazine) – Micromanaging your teen's spending will undermine his independence--and make both of you crazy. But you don't want to be surprised by a $600 cell-phone bill either. One solution: Limit your child's outlays automatically, offering him the freedom to spend as he wants within limits. BY JANET PASKIN

1 PREPAY THAT CELL PHONE

» STRATEGY Pay in advance for a set number of minutes and text messages on your teen's cell. When the money is up, so's the talk time.

» COST A typical teen bill will likely run $60 or so a month. Some carriers let you automate monthly payments from a credit card.

» BONUS Your teen can still reach you in an emergency after his minutes are up if you choose a plan from your own carrier that offers unlimited calls to other customers.

» STRATEGY Load a preset amount on a Visa Buxx card (visabuxx.com) through automatic monthly transfers. The card can be used like a debit to pay for even small purchases, like a latte.

» COST Fees depend on the issuer. They may include sign-up ($10 to $15) and reloading charges ($2 to $2.50), as well as annual fees ($15).

» BONUS Teens can track their spending and check their balances online--and so can Mom and Dad.

» STRATEGY Set up an iTunes allowance for your teen--an Apple account linked to your credit card--and authorize Apple to replenish the account by a set amount each month.

» COST Nothing beyond the amount you choose to put in

» BONUS The money stays in your teen's account until she spends it.

» STRATEGY You can buy gift cards or certificates at most malls in any denomination for use at any store. Use them to put your teen on a mall budget--once the card runs out of money, he's done spending.

» COST Expect to pay a small fee, typically $1 to $6.

» BONUS Your teen won't be crawling the mall with a pocketful of cash. If the cards are lost or stolen, they may often be replaced.

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