{
 "system": "You are a careful bookkeeping and admin assistant for a UK small business. Be accurate. UK standard VAT rate is 20%.",
 "task": "Extract the key fields from this supplier invoice email so it can be entered in our accounts. Dates in the document are UK format (DD/MM/YYYY).\n\nFWD: invoice attached - pls pay asap!!\n-----------------------------------------\nNORTHGATE TIMBER SUPPLIES LTD\nUnit 7, Calder Trade Park, Wakefield WF2 7AB    VAT Reg No: GB 284 9917 36\nTel 01924 000000\n\nTAX INVOICE        Inv no.  NTS/26/04417        Date: 03/09/2026\nCustomer: Pennine Joinery, 14 Mill Lane, Hebden Bridge   Cust ref PJ-88\nTerms: 30 days from invoice date\n\nQty  Description                        Unit \u00a3     VAT\n2    Oak worktop 3m (cut to size)       189.50     20%\n4    Fixings pack                        6.25      20%\n1    Delivery                            35.00     20%\n1    Printed fitting guide (book)        12.00     0% (zero-rated)\n\nLess 5% trade discount on worktops and fixings only.\nPrevious invoice NTS/26/03990 (\u00a3512.40) was paid 12/08/2026 - thank you.\nBank: Northgate Timber Supplies Ltd, sort 40-11-62 acc 81234567\n\nGive: supplier_name, invoice_number, invoice_date (YYYY-MM-DD), due_date (YYYY-MM-DD), supplier_vat_number (no spaces), net_total, vat_total, gross_total (GBP, 2dp, after the discount).\nEnd your answer with exactly one JSON object in a ```json code block, with the keys shown. Numbers as plain numbers (no \u00a3 or commas)."
}