If you have a small business that currently doesn't accept credit cards (or just want a way to swipe credit card payments on-the-go), mobile apps like Square and Intuit's GoPayment allow you to take credit cards via your smartphone when paired with a magnetic stripe card reader. We'll take a look at both apps (and their processing fees) to see which one may work best for you.
Both Intuit and Square will send you a free card reader once you are approved for their services. Square users are sent a small postage-sized card reader that plugs into your smartphone's headphone port. While GoPayment currently has a similar card reader that plugs into the headphone port, you can also purchase a sleeker-looking card reader like the Mophie Marketplace ($79) that connects through the dock port.
The nice thing about Square is that its processing fees are dead simple and they take all credit card types at the same price. When you swipe a credit card, Square takes 2.75% of that transaction with zero monthly fees. Keyed-in cards (typed rather than swiped) are slightly more per transaction, at 3.5% + $0.15.
GoPayment offers two types of plans: Low-Volume and High-Volume. Low-Volume is for people who take in less that $1,000 per month and High-Volume is for anything more than that. Low-Volume is 2.7% + $0.15 per transaction. The transaction fee for High-Volume is 1.7% + $0.30, plus a monthly charge of $12.95. Keyed-in transactions are 3.7% for Low and 2.7% for High.
GoPayment's plans are a bit complicated and have different charges altogether for American Express. Because of its integration with QuickBooks (also by Intuit), GoPayment seems geared toward small businesses. While Square can be used for businesses, it also works well for small personal transactions between friends.