Adding commission field to sales invoice

Want to add a new commission feild to the sales invoice which is to be calculated based on percentage we specify let’s say 5 or 10 based on the contract with the client

Further vat is to applied on sum of (totol+ commission)

Grant total should show total+commission +VAT can some one advice how to achieve it

Custom fields cannot be used to perform calculations.

If you want to add commission to a sales invoice and apply VAT to it, that must be a separate line item. While the commission will be shown as a line item, it cannot appear separately below the total.

Tax is not calculated in Manager based on any total. By necessity, since items might be taxed at different rates, taxes are calculated per line item and added in the totals section.

If we take commission as a separate line item can we use it for different commission rates like VAT and can the total for commission appear after total and before vat total at the bottom on the invoice

Can we add two tax codes on a given line item if yes we can define commission as a task code and it we added to the line item

You can apply any tax code to any line item, as long as the tax code has been added under Settings.

No. I already answered that question.

No.

Even if you could, that would be wrong, because taxes are posted to Tax payable account.

You could define commission as a non-inventory item. See Manager Guides. But it will still be a separate line item.

i can attach the commission code to an income account , now is there a way to add dual TAX code to an invoice

I already told you this is wrong. The result will be calculated, “fake” taxes. As you have apparently set things up, they will go to a custom control account. You say this is an income account, but I suspect it is not, because you cannot assign tax codes to income accounts. The processing of tax code calculations is hard-coded into the program, and you will be distorting your financial records in many, unpredictable ways.

I already told you no.