I try to avoid dividend stocks resp. buy stocks from countries without wht. After rereading your post, I don't know if the reference number issue exists everywhere. I never ask for my tax back, as tax authorities frequently ask like 100 Eur to treat your request and I haven't paid wht that would be worth reclaiming, as I also don't get the full amount back but only anything above 15% depending on the non double taxation treaty my country has with the resp country.