overpaying retirement accounts

[joenorm]

I have a Simple IRA setup with my employer. The limit appears to be $13,500 per year.

I pick a percentage of my paycheck to be deposited into the account per month and I sort of guess(I'm sure there is a better way) so as to max it out by the end of the year.

I was wondering what happens if I overpay? Who's watching? Who monitors this? Is it the IRS and they are tracking every cent? When would I ultimately be informed I was overpaying? This question goes for all retirement accounts.

Thanks

[zolotiyeruki]

Vanguard has a rather nice page outlining what happens if you overcontribute, and how you can correct it (and the consequences if you don't).

[seattlecyclone]

Payroll systems will often cut you off at the limit, since reversing excess contributions can be a headache for everyone involved. Of course if you switch jobs partway through the year your new company will not be aware of how much you contributed toward your old company's plan, or whether those contributions apply toward the same limit as your new company's plan operates under.