I noticed that shutterstock was nice enough give us a nice report for our earnings in 2015, which makes for filing taxes easier. Fotolia & Istock doesn't withhold anything, but I can easily export a CSV of my earnings, so they're not too painful.
The only agency that's bothering me is 123RF. They withhold taxes for each image sold, but I haven't gotten a report from them. Do they usually generate one so I don't double pay my taxes?