You're right, I don't know why I called them vouchers, similar to the PS vouchers I print for folks who mail in their taxes and estimated taxes. Yes I fill them out by hand (name, SSN, address is all), have the client sign & date, sometimes both spouses. I sometimes mail several clients' in one envelope to save on postage. Old school. It makes life easier for all in future years. I detest printing out estimated payment vouchers. Old folks who live on hefty investment income and don't use online payments also forget to send in estimated payments. So I use SSA often at 22% withholding to cover large investment income.