Starting with manager, got questions

Hello, I just came across this awesome software and i gotta say, i am happy I found it. Great work by developers. (I am actually thinking of buying the Linux server edition, but first need to get familiar with it).

Anyways, i owned a IT Consulting and repair shop business, so I need some assistance to set Manager correctly. so my questions are:
1- How to record a refund from a supplier/vendor on a expense account (non inventory) transaction made with payments: example full refund for a bank charges
2 . in the other hand, how to properly record a refund from supplier for a Non-Inventory item such a computer part needed to repair a computer?
3-in our business we use square for credit card payments, however square final transactions are posted on my bank feeds without the square fee, in other words, if we sale a item or services for $100 and customer pays with credit card, square sends only 97.25 dollars to our bank, so what type of account is the square fee? perhaps “liability account”?
4-we do have partnership with different companies, for example we resell software, and we gain residuals every month, how should i categorize this accounts? Perhaps COGS?
5-and Finally for now, how to create a sales tax report, here in US we need to pay sales tax either every 3 months or yearly.
thanks, i am sure ill come back with more questions as i continue exploring this software.

1 & 2 - see Use debit notes for supplier returns and refunds | Manager
3 - no; your Square fee is an expense, not a liability; see Record a receipt | Manager; Receipts against sales invoices. You will record the payment to your customers’ invoice, and add in the difference for the Square fee to an expense account (these types of fees are tax deductible so I would advise against passing them on to your customers, but that is up to you).
4 - this statement is not clear to me; to whom do you resell; or are you reselling for someone else (a consignor)? Generally “residuals” are an income source. In that case these would be a revenue account; see Design a chart of accounts | Manager.
5 - see Create and use tax codes | Manager, then run reports from Reports>Tax Codes… in the program.

Spend some time searching and reading the guides at Guides | Manager; much of what you are asking about will be covered there

It also sounds as though you may need the assistance of a qualified accountant. I recommend finding a local CPA firm that has practitioners who specialize in financial accounting and reporting, not just tax (ask if they have “assurance” or “outsourcing”); they will be better able to help setup your books than anyone here.

thanks for your reply.