Not sure if this was psuedo-code or the real deal, but note how I defined the search column. I also used single quotes around partner.

var filters = new Array();

filters[0] = new nlobjSearchFilter('custentity_account_id', null, 'anyof', '333476');

var columns = new Array();

columns[0] = new nlobjSearchColumn('internalid');

var partner = nlapiSearchRecord('partner', null, filters, columns);

Otherwise, it should work. On a related note, I recommend referencing an existing saved if there is complicated logic or a lot of columns. If you're only getting a couple fields and you know the partner you're looking for, you might use nlapiLookupField.

Check out the page in HELP called "Search Operators." Different search operators are valid for different data types, so you may be getting this error because the custom field's data type is not compatible with the anyof operator. For instance, if the data type is numeric, then you would actually want to use the "any" operator.

I appreciate your help, even though what you provided is nearly identical in fuctionality. Since this is java script, using single or double quotes really doesn't matter. I have other code that works with both single and double quotes. This code works, but only searching internalid. I cannot get this code to work with custom fields.

var ids = new int[] { 144110 };

var filters = new Array();

filters[0] = new nlobjSearchFilter('internalid', null, 'anyof', ids);

var columns = [

new nlobjSearchColumn('internalid')

];

partner = nlapiSearchRecord("partner", null, filters, columns);

Does the default form for the role you're using for SuiteScript show the field in question?