Help with default fields

Hi, I want to customise default fields in Customer coloumns in manager software. How shall I proceed? I want something like this.

  1. (Sr.no) first

  2. Description of item
  3. Size
  4. HSN code
  5. Tax rate
  6. Total.

How i can customise?

there is a guide to add line numbers. search the guides section.

if the inventory item was created without an Item Code, the Description of the same is shown.

what do you mean by size? please explain. if it is something that is not already shown in the sales invoice, create a custom field as a line item of sales invoices under settings. check the guides section for instructions.

create a custom field for inventory items called HSN. then if you have saved a HSN code for any inventory item, it will automatically show as a column in the sales invoice.

Total appears as the last column already.