Hi, i use Mollie (Netherlands). I have around 20 orders a day, but already 3 times at the same time giving me problems.I use your code, that is perfect for me, but it needs to check if the reference number does exist. So i think i need a part of the code that is posted by Fertechpl.So my reference isML121500 (order id is 500)The next one will be ML121501. Now a second customers comes on the the site, and is paying before the one that started payment first. This will give a problem.So for that i need the reference to be changed to QML12150Q or somethingML121500 (order id 500)ML121501 (order id 501)ML12150Q (order id 502)ML121503 (order id 503)Can you help me with that?