Inconsistency in rounding of Settlement costs in Invoice PDF

[holtkamp]

Specifications

• API Version: v1

Describe the issue

Is there any documentation available about the way Mollie applies "rounding of values"?

The reason that I am asking is an inconsistency I noticed when processing Settlements in a (Moneybird) Administration.

Situation For a certain Settlement X, these are the costs as returned by the API:

"costs"] => array(1) {
    [0] => object(stdClass)#18432 (5) {
      ["description"] => string(5) "iDEAL"
      ["method"] => string(5) "ideal"
      ["count"] => int(17)
      ["rate"] => object(stdClass)#18453 (2) {
        ["fixed"] => string(6) "0.2900"
        ["percentage"] => NULL
      }
      ["amount"] => object(stdClass)#18141 (3) {
        ["net"] => string(6) "4.9300"
        ["vat"] => string(6) "1.0353"
        ["gross"] => string(6) "5.9653"
      }
    }
}

Note that the gross amount has a value 5.9653.

PDF Version of Invoice When looking at the PDF version of Invoice Y that covers this Settlement, the gross costs of Settlement X are indicated in the list of Settlements as "deductions" of €5.96

So 5.9653 gets rounded to €5.96, where I would expect €5.97

The strange thing is, a value like 6.3162 is rounded to €6.32, as expected...

Administration => Settlements When looking at the Settlement X in the dashboard, the "deductions" column indicates €0.00, while the "costs" column indicates €5.97, so this is different Settlement entry in the PDF Invoice... strange!

Is this caused by rounding compensations? This particular Settlement is at the beginning of the month / last of an Invoice. The "revenue" minus "deductions" does match the amount that is "paid out", so I suspect some rounding mechanism to be at work. Is this documented somewhere?

[willemstuursma]

Hi @holtkamp, can you send me an email on which settlement this issue is with, I'll have a look at it: willem@mollie.com.

[holtkamp]

did you guys find anything? I come to the conclusion that the "sum of all Settlements" (which might be on a daily basis) might not be exactly the same as the the amount that is processed in the monthly Invoice. This makes the financial accounting part of the Settlements difficult...

[willemstuursma]

Sorry @holtkamp I didn't have time to look into it yet. Spend most of last week in London on the OWASP AppSec conference.

[holtkamp]

Monthly bump on this, encountered this again on the new Invoice 🤓

[willemstuursma]

@holtkamp it's not forgotten, I'll let you know if there are any updates.

[willemstuursma]

@holtkamp This issue has been resolved. The problem was a rounding error on the PDF invoice.