Most of the larger places in the US will cost you around $4-6 per employee. 5000 is a lot, so I'm sure you'll find someone who will negotiate. So to do it "right" and full-service from a named payroll company, I'm guessing $20,000.Now retail, maybe $2-3 of that is for e-filing services and $2-3 is for printing/mailing. So if employees are printing their own, getting emails, or getting links to a secure FTP site, then maybe you can save half of that by not mailing. Check the rules, but that's pretty common. For the other half, I'd bet plenty of companies have really good deals, including the IRS--I'd bet money they allow you upload a 5,000 line CSV for free or next to it.Of course there's India and stuff--real outsourcing--but I'd have to quintuple check the legalities of sending employee information across international lines, HIPAA and all that. And even if an international outsource printed and enveloped it, you'd have to have it flown here to ship, and you'd have to solve the e-file aspect. As with everything it's a trade-off of how much risk you want to pay to transfer.So negotiating in the real world, I'd bet $10,000 to do it right. These are guesstimates--not quite guesses, but not quite estimates, but a start for your thoughts. Hopefully a payroll accountant will strike me down.