You are confusing a "Counter Offer" and an "Addendum".
A Counter Offer, may void an existing contract, not an Addendum.
You can disagree to the Addendum, and the buyer then has to decide whether s/he
still proceeds with the contract or back out.
Also check with your agent to explain the differences between
a "Counter Offer" and an "Addendum".
This is a seller's market. You shouldn't be getting pushed around by the Buyer. It's actually the other way around. You are the one with the upper hand. You don't have to agree to any Addendum from the buyer. You can just say No to the buyer's requests, then put in a Notice to Perform that tells the buyer that if they don't remove their contingencies with the original contract and terms, you reserve the right to cancel the contract and find a new buyer.
Typically, an addendum submitted by one party after a contract has been accepted only becomes effective if all parties agree to it. If one party does not agree, then the addendum is not valid and the original contract remains in effect.
Your bigger issue is that of tenant's rights. If you gave your tenants a move out notice with a move out date of say March 30th, you can not give them another notice changing the move out date to March 10th. You can ask if they would move earlier, you can offer to compensate them, but so long as your tenants are not in breach of their agreements with you, you must honor those agreements.
There's no law against "re-opening negotiations" when you have an executory contract, people can change their agreement. Typically, agents discuss these addendums before springing them on the other party, but that's beside the point.
You can say no, and you are still bound to fulfill the terms of your agreement with the buyers. If you want to back out of the sale, consult an attorney.
All the best,
Simplified version is that you can't get out of the contract by simply refusing to sign the addendum. The buyer still can perform up to the letter of the original contract and close as it was planned originally.
At the same time if the buyer is not satisfied with the progress and your cooperation you may be able to negotiate a cancellation of the contract.
David Rivas' answer is right on point. Don't forget the tenants have rights and your should review the contract to make sure their rights are honored. If there is a violation of their rights in the contract as it is now written, by say having the tenants move out before the end of their notice period, the tenants can stand o their rights and prevent you meeting your obligations to the buyer. So now is the time to review the entire contract as it is now written with your Realtor or an attorney.
John J is spot on with his answer. Unlike a "counter offer," the act of an addendum does not affect the current contract terms or conditions in any way. The buyer can ask, but since the contract has already been signed and agreed by both parties, then the contract is as stated. If you agree to the addendum--which, at least only from the facts you've provided, it appears you don't have to so agree--then and only then would the new terms be incorporated into the existing contract.
But as David Rivas pointed out, you DO need to confer with your agent about this. As we do not know the exact terms of your contract, we can only "generally" conjecture what the right answer will be. If you've agreed to terms in the initial contract to "move up" the escrow closing, then you might be required to accept an earlier closing date. Again, only your agent and, if necessary, the agent's broker will know the answer fo you on this one.
Talk to your agent, and get the best information you can regarding the addendum and whether or not a modified addendum could be offered from you to the buyers.
Allison James Estates & Homes