0005420: VAT calculation not precise enough (rounding differences) in basket - OXID eShop bugtrack

ID	Project	Category	View Status	Date Submitted	Last Update

0005420	OXID eShop (all versions)	1.02. Price calculations (discounts, coupons, additional costs etc.)	public	2013-09-19 12:26	2014-02-11 16:55

Reporter	tapesandmore	Assigned To
Priority	high	Severity	major	Reproducibility	always
Status	resolved	Resolution	unable to reproduce
Product Version	4.7.7 / 5.0.7
Fixed in Version	4.7.10 / 5.0.10

Summary	0005420: VAT calculation not precise enough (rounding differences) in basket
Description	Item VAT calculation process calculates based on the item gross price already rounded to 2 decimals. This causes rounding issues in the basket’s gross total. Detailed explanation: In the backend you enter the net price per unit. OXID automatically calculates the gross price per unit with a rounding precision of 2 decimals. In the shop basket OXID uses the gross unit price (rounded from net to gross with 2 decimals) and recalculates the net price (precision 5 decimals). At this point you get small rounding issues that lead to a different gross total calculation compared to a calculation a ERP-system like NAV2009R2 does. What OXID 4.7.7 does:%) Gross unit price (rounded from net to gross with 2 dec.) + VAT = net unit price (precision 5 dec.) * quantity = net total + VAT = gross total What NAV2009 and many other ERP-Systems do: Net unit price * quantity= net total + VAT = gross total In order to get a better overview please find enclosed an excel sheet with a samples calculation and a screenshot out of OXID 4.7.7 confirming that problem.
Tags	No tags attached.
Attached Files	Oxid vat calculation.zip (104,190 bytes) Oxid config Tapes&more.jpg (193,254 bytes) Oxid config Tapes&more.jpg (193,254 bytes) rounding.png (97,575 bytes) rounding.png (97,575 bytes)

Theme
Browser	All
PHP Version	any
Database Version	any

ray 2013-09-20 10:40 reporter ~0009102	uploaded file from closed duplicate

tomas_liubinas 2013-10-10 15:15 reporter ~0009147 Last edited: 2013-10-10 15:16	As I understand your suggestion introduces inconsistency in price calculation. Basically the price for multiple products would not be equal to amount * displayed-single-product-price. For shop visitor who is not aware of shop internals that would look incorrect. In this case price calculation consistency is taken into account. Therefore this is not a bug. I see there is another problem with this example, I reported it as a separate bug 0005465.

tapesandmore 2013-10-14 09:04 reporter ~0009151	You are right, it is not a bug. What I was trying to explain is that the oxid shop has a very interesting way of calculating the VAT. I had a look at the posted issue 0005465 “Price rounding precision is hardcoded to 2” – I am not sure if extending the precision to 5 would solve the problem. I think we have to try it. Otherwise the whole calculation should be reviewed.

Linas Kukulskis 2013-11-05 16:48 reporter ~0009228	fixed together with related task

tapesandmore 2014-01-08 11:42 reporter ~0009390	Update to 4.8.1 didn't solve the problem. Rounding issues are still present.

Linas Kukulskis 2014-01-09 16:37 reporter ~0009401	hi, i checked this ticket again. and noticed that you configured system like this: 1. price entered in brutto mode 2. price are shown also in brutto mode in such situation all calculations are done in brutto mode. and netto price is calculated from brutto as you show in xls sheet. to eliminate this calculation problem you can configure shop like that: 1. price enter in netto mode (master settings->core settings->settings->vat->Enter Product Prices as Net Prices (plus VAT)) 2. price are shown also in brutto mode then total sums will be the same as in NAV; also eShop support all possible variant enter/show prices: netto/netto; brutto/brutto; netto/brutto; brutto/netto; other note: all calculation are done in such mode in which prices will be show;

tapesandmore 2014-02-11 08:40 reporter ~0009489	Hi Linas, thanks for your suggestions and help. But our shop is already cinfigured that way. Uploaded an image of the config part. Best regards Bastian

Linas Kukulskis 2014-02-11 16:55 reporter ~0009492	sorry, but i cant reproduce; just tried once again and uploaded print screen. it seems work fine my configuration: price enter netto mode, view brutto also configured show 5 digits in master settings->core settings->settings->other settings->currency: EUR@ 1.00@ ,@ .@ €@ 5; maybe you are using extensions?