Hi Cheng Wei > Please find attached a zip file containing: > > - A company data file (AccountRight Enterprice v19+); > - A sample invoice pdf generated by our system; > - An MYOB Item Sales import file generated by our system, > containing line items of the invoice. > > Invoice Number: GR2115
Very interesting. As it turns out, from that invoice it would appear that MYOB uses the same GST rounding model that we use in our product, Accredo. Our algorithm is a line-by-line GST calculation rounding to nearest BUT with flowthrough accumulated roundoff. The result of this algorithm is that you get exact whole cents on each line which is ideal for accounting analysis but the resulting total GST is also consistent with rounding the whole document total just once. To get an idea of how this algorithm works on a line by line basis: The 1st line is $272.16, add 15% = $312.894, rounds to $312.89 and 0.004 difference. The 2nd line is $28.88, add 15% = $33.212 + 0.004 diff = $33.216, rounds to 33.22 and -0.004 difference. The 3rd line is $80.00, add 15% = $92.00 - 0.004 diff = $91.996, rounds to $92.00 and -0.004 difference. The 4th line is $589.50, add 15% = $677.925 - 0.004 diff = $677.921, rounds to $677.92 and +.001 difference. The 5th line is $58.95, add 15% = $67.7925 + 0.001 diff = $67.7935, rounds to $67.79 and +0.0035 difference. The 6th line is $60.55, add 15% = $69.6325 + 0.0035 diff = $69.636, rounds to $69.64 and -0.004 difference. The overall GST total = $163.51. Note that this result is the same as taking $1090.04, add 15% = $1253.546, rounds to $1254.55 and -0.004 difference. In each of the above examples, I'm showing the inclusive total which is how MYOB stores it per invoice line but you can also just calculate GST at 15% and round that with the flowthrough model which is what Accredo does since they are mathematically equivalent. I'm not sure if MYOB also handles negative documents consistently and rounds exact half cents _down_ for credits which is something we also factor into the algorithm in Accredo. We like our negative invoices to give the exact same figures as an equivalent positive invoice with just the signs flipped. If you use standard IEEE round-to-nearest, you won't get that for documents with lines that have exact half cents of GST. I'd need an example of an equivalent credit document to confirm MYOB's behaviour in that case. Cheers, Paul. _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe
