Several states now require tax withholding either as requested by the customer or mandated by the state if federal whithholding takes place. Form 1099-R has a place to print this amount and also a place for the state abbreviation and State ID number (Box 10 and 11). According to the IRS instructions for form 1099-R, "The state number is the payer's identification number assigned by the individual state."

Now the question -- short of contacting the tax department of each state, is there a central location that provides the format for each state ID number? I'm looking for length (number of characters) and format (numeric vs. alphanumeric).