The title of this thread has been edited from the original: All I want to do is run a transaction
I just want to run a credit card for payment that I'm taking from a customer over the phone
You can run manual transactions whenever you need to. Just follow the usual steps to ring up the order, then on the transactions screen choose "Manual Credit Card Entry." You'll need the card number, expiration date, CVV code, and billing zip code of the card to complete the transaction.
I do recommend checking out Square's Manual Card Entry help page and Best Practices page if you're planning on running a lot of manual cards.
Hope this helps!
Square Community