While it is important for children to learn the responsibility of holding down a job and saving money for such things as cell phones or MP3 players, 12-year-olds aren't old enough to get a work permit. Fortunately, there are other ways a 12-year-old can earn a few dollars to purchase the latest Wii game, or save up for a car when it comes time.
Clean a few houses. Adult housekeepers cost a fortune, and many young parents and elderly couples can't afford it even though they need the help. A 12-year-old is capable of cleaning and earning a few extra dollars for it. The amount of houses you can take on each week depends upon your homework and sports schedules.
Become a vacation helper. According to the website Education, a 12-year old can help a family out when they go on vacation. Once per day you can go over to the family's home and water the plants, collect the mail, and care for any pets. Just send an email out to all of your friends and family members with your going rate, and when they decide to go on vacation, hopefully they will give you a call.
Deliver newspapers or hand out flyers for businesses. If you have a bicycle, you can make deliveries or perform cheap advertising for some local businesses by handing out coupons or flyers listing the store's current specials. You can charge by the hour, or by the job.
Offer your services as a tutor. Make a list of the things you are good at. If you are good at math, become a math tutor. If you are gifted in art, become an art tutor. If you are the MVP of your soccer team, become a soccer tutor. You can tutor other 12-year-olds, or children who are slightly younger than you are, who just need a little help to catch up to everyone else. You can set your rate per hour or per session.
Sell baked goods and bottled soda or juice. You may need to borrow money from your parents to get started. Baking items from scratch is inexpensive, and you can get a 10-pack of juice boxes for cheap. Place all of the items in a wagon and walk around your neighborhood shouting that you have these items for sale. You could also bring a CD player and play the same music as the ice cream man.