"I am filing a 1120S form that has two single member LLC's it owns 100% that act as subsidiaries, is there a federal form for showing the consolidation of the LLC EIN's with the S corporation I need to file along with 1120S"
No. The single member LLC's are treated as disregarded entities and as such are no different than a division of a company. The IRS should already have this information when you set up your LLC you should have listed the S corp as the owner.
The LLC's were multi-member at set up with the S Corp as the manager/member. The S Corp absorbed the related members minority interest when the other member was withdrawn to fully own 100%. Each LLC became a single member LLC owned 100% by the S corp. Is there a form to file with the IRS to denote this change? We have prepared the 1120s as a consolidated entity tax form for these single member LLC's but are unsure what do with entity EIN's to make sure we don't have to file any other form but the 1120S.
The EIN's for those entities do not need to be reported anywhere within the form 1120-S tax return.
It is recommend that you include a statement with the final LLC tax return explaining the transaction and that the entity will continue as a single-member LLC under the EIN of the S corporation member.