The day of paying your tab with your iPhone has come, and despite today's rollout of Apple Pay, not all expected stores are on the shopping list.

According to the Wall Street Journal, more than 220,000 stores or apps will now take the Apple Pay and your fingerprint as a means of payment.  Companies including McDonald's, Whole Foods and Walt Disney World have already signed up.

But one glaring omission is the nation's largest retailer, Walmart is not taking Apple Pay as a way to settle your bill.

But why?

Wall Street Journal said it's because few of the company's registers have the capability of reading the radio signal that makes the app work.  Also only the newest phones,the iPhone 6 and iPhone6 Plus, have the technology that produces the signal for brick and mortar stores.

While, 222,000 merchants are ready to take the technology, Forbes discovered there are 8 million retail points of sale.

Another omission in the technology, not all cards will be compatible with the system, yet.

According to Forbes, only the nation's largest banks, like Bank of America, Capital One and Citi, have signed up.  Many smaller, local banks and store credit cards are not part of the initial rollout. Neither are prepaid and corporate cards.