Thank you for your reply. After hours and hours of doing my very best to rectify every potential fault discoverable on my zoho Spreadsheet containing the first 100 invoices exported from Invoice2Go to my Downloads folder, having removed all the email addresses attached to my my Invoices since QBO doesn't want to accept them, and having re-written every description so that it only occupies a single line on the spreadsheet, I have finally arrived at a single error from QBO which has me utterly dumbfounded:
Some Rows Need Invoice Numbers:
When an invoice has multiple rows, enter the same invoice number in every row that's part of that invoice.
This seems ludicrous. There AREN'T any multiple rows. Everything has been simplified to occupy no more than a single line as I have mentioned already. The only potential reason I can think of is the somewhere between 10 and 20 missing invoices which went went badly for me back then, and so for example Invoice 1 and 2 are simply missing, but that's because I simply used the next Invoice available instead. I originally tried to include the missing invoices by giving them a "Void" text in the Name column, but QBO wasn't having anything in the Amount columns that either stated N/A or 0 for GBP value. So I ended up removing them.
I'm slowly losing the will to live on this project. QBO is unbelievably inflexible, or so it would appear...
