A tip to use with Square, which charges a 2.75% fee. When adding the fee onto the customer's bill (because you aren't going to pay that

) you divide the total by .9725
For example, the job total is $800. You do the following:
800 / .9725 = 822.62
That is the total that you charge on Square.
Now to prove our math, $822.62 is what Square will charge the persons credit card, then they will take their 2.75% from that:
822.62 X .0275 = 22.62
After they take that $22.62, you are left with your $800.
If you had just added 2.75% of $800 onto it, you would have gotten $22. Losing that 62 cents might not seem like a big deal, but for accounting reasons it's better to keep it accurate. You are going to need to keep track of those fees so they could be written off at the end of the year and you don't want them digging into your gross.
So remember, divide by .9725
I actually wrote that right on the Square card read so I don't forget.