is there any workaround to get the internal id for a vendor in an income statement saved search? I tried just adding “id” (transaction.mainname.id) but I got an error

Try this formula text: {vendor.internalid})

Note there are two different vendor values, the "header" value that's on bills, payments, etc and the "line" value that's on JEs. And maybe bank deposits, bank checks, etc if you have those. You'll have to double-check me on that. Anyway the line value is {vendorline.internalid} in addition to what mesper noted above. I usually do a case statement something like

case when {vendorline.internalid} is null then {vendor.internalid} else {vendorline.internalid} end

thank you! it turns out this is for a multi-book accounting transaction search. is this at all possible for that?

Is your starting node the Multi-book accounting transactions or whatever that one is called? I no longer have access to an account with MB in it to grab what that's actually called. Ok then your first attempt makes more sense. I'm surprised what you tried didn't work. It does in a lot of cases. Just crossing i's and dotting t's: you are putting that in squiggly brackets, ie {transaction.mainname.id}, not in regular parentheses, in your formula, right? If not, that's definitely your issue. Also I'd assume you're doing Formula (Numeric)? Type mismatch could be an issue too. If none of that fixes it, it could be some limitation inherent in starting at the Multi-book node. You might have to use an Analytics Dataset instead