I think I have a big problem and am praying there is a quick solution. We are not VAT registered but I have entered all of our purchase invoices with the T1 tax code so obviously our figures are all wrong now. Does anyone know of a quick way of changing the tax code for all of our purchases to T9? Please don't let me have to go through every single transaction and edit it... Now I know why I had intended to do a Sage course before I started keeping books...
The easiest way to correct this without amending every single transaction individually is to print the detailed day book report for supplier invoices (go to suppliers, reports, day book reports, day books: supplier invoices detailed). This report lists all the purchase invoices you have posted on for any given date. Most importantly it separates each invoice between net, gross and vat, and also states the nominal code you have posted the invoice to. The report will then be printed to the screen. Export this to Excel using the export button. It's best to export the data as a CSV file.
In Excel you then need to sort all of the data by nominal code (highlight the data and then go to data and sort). Sort by the column which the nominal codes are in. This will then sort all invoices in order of nominal codes, i.e. you will have all the 5000's together then the 5001's, 6000's etc. You then need to add up the total 'VAT' amounts of all invoices posted to each class of nominal code i.e. add up all the VAT amounts of each invoice with the nominal code 5000 and so on. The quickest way to do this is to use the formula '=sum(with the range you want to add up in brackets)'. When you've done this for all nominal codes, check that the total of all these added together agrees to the original total Input VAT for all purchase invoices as shown at the bottom of the day book report.
You will now have a list of nominal accounts with totals next to them. To correct your trial balance post a journal in the nominal ledger. Simply debit each nominal account with the total VAT that you calculated above. You then need to credit the purchase tax control account with the total Input VAT (as per the original day book report). You will then have made the balance on the purchase tax control account NIL, and posted the correct amount of VAT to each nominal account. In effect the gross amount of each invoice will now be sitting correctly in each nominal account.
Hopefully this makes some sort of sense . Obviously if you've only got a few invoices, probably less than 20, you'll probably find it quicker to change each purchase invoice manually in the maintenance area. If you've got a lot of invoices (maybe a few hundred if you posted them in batches) then in my opinion the above method will hopefully be the quickest for you.
I wish I had know your brilliant solution when I first started out, in a blind panic I pressed the rebuild button and started from scratch - oh what a headache I had !
I have printed off your reply and put it in my `accounts useful solutions file`.
. Obviously if you've only got a few invoices, probably less than 20, you'll probably find it quicker to change each purchase invoice manually in the maintenance area. If you've got a lot of invoices (maybe a few hundred if you posted them in batches) then in my opinion the above method will hopefully be the quickest for you. 
