IRS say file 1120 but 1120s was filed instead

[AZ-Tax]

Aug 2009 CP575A (EIN approval) letter from IRS says file form 1120 due by 3/15/2010. I just acquired this TP as a client. Upon looking at TP's 09 personal and busiess tax return, the CPA who filed TP's 09 bus tax return, filed form 1120s. So when I amend TP's bus 09 tax return, do I amend with 1120s or amend with 1120. Cant say I ever saw this before.

Update: I did a quick search that a "incorporated" bus can elect to be taxed as "S-Corp" vs "C-Corp" via form 2553. Need to locate letter from IRS regarding this.

[joanmcq]

The EIN is going to be for an 1120; the filing of the 2553 usually comes later; after the EIN is applied for. Otherwise you don't have a tax ID number to put on the 2553! Verify the 2553 was filed and accepted and then go on filing the 1120-S.

[Y2KEA]

It appears you have the SS4 acceptance letter. The 2553 may have been filed & TP did not give you a copy of the acknowledgement
.
Was the 1120S efiled and/or did the CPA check box H(5) on the 1120S? If so, the S election has been accepted.

[AZ-Tax]

Yes, H - 5 on form 1120s is checked.

Thanks for every ones help

[Burke]

If "S" status was not elected, he will, or would have already heard from the IRS, when the first return was filed. They will let him know he filed incorrectly.