What is common shortcut for “quantity”?

Question

I found on an invoice the shortcut QTTY that stands for the word quantity.

Simplified part of the invoice:

Item      |    QTTY Unit | Unit Price |Total Price
Product X |       2      |   100.00   |   200.00
...

Would you use QTTY or QTY? Or any other form?

Answer 1

I would say that QTY is used more commonly, though looking through a handful of invoices I have to hand, they all use quantity instead of an abbreviation.

Answer 2

Just say Unit Count for your fixed column. And please don’t abbreviate quantity.