You need SSN of the payee to submit an information return - on the 1099-misc form.
You may mail the form to the last known address by certified mail and keep the receipt.
If you do not sent the form 1099-misc to the payee - you will be a subject to a penalty of $50 for each form.
You might be also a subject of the same penalty for an incorrect or missing TIN on an information return.
See page 12 instructions - http://www.irs.gov/pub/irs-pdf/i1099gi.pdf
Let me know if you need any help.
Reporting the payment on the form 1099-misc and claiming the business expense - these are different issues. Your original question was about filing 1099-misc form.
Your supporting documents for business expenses should show the amount paid and that the amount was for a business expense. Documents for expenses include the following:
Also if W-9 form was not filed - the payment to a subcontractor is a subject of 30% income tax withholding.
If you do not have supporting documents or they are not sufficient - the risk is that in case of audit your deduction might be disallowed.
Sorry if you expected a different answer.