They have an initial limit that's all.  I think it's something like $1500 per day.  Understand that most people who are using Square are doing $5-$20 at a time..It takes a long time to get to $1500 that way.

I had the exact same issue when I initially signed up with them.  They send some paperwork, you fill it out and they bump you up to $25k.

With Square, unless it's Friday, 100% of the time you'll have your money the following day. And if you're in a pinch, they'll deposit the money into your account instantly for a larger percentage.  Not that I'd necessarily want to use that feature, but for somebody who might be in a pinch, it's a great feature.

They also do loans that they'll deduct 10% from your credit card transactions.