Can they do this??

What is the name of your state? Missouri

Our small janitorial company signed a 1 year contract as a sub-contractor on August 23, 2004. As of today, October 3, 2004 (Sunday), I received a call from my contact person that the contract is ending today. We were instructed to remove all our equipment because the corporate office of the department store has hired a national company to service all the stores. Our signed contract requires a ten (10) day written notice of termination from either party. The call was received with a one (1) hour notification. We were reassured that this decision played no part in our duties of service and that the store managers were very satisfied with our work.

We were paid through the end of September, but our payroll is going to roll back into the last week of September and the first week of October. We have already issued an invoice for the full amount of services rendered for the month of October to cover this payroll period and calculated this into our accounts payables for payroll, taxes, workers compensation, etc.

What if any, responsiblities is the company who hired us accountable for? Will this breach of contract make them liable to remit the October invoice in full?

Without reading your contract there's no way to know. If the notice contingency is not backed up with penalties for failed notification, then basically all you have is a lawsuit to let a judge determine when the contract actually ends.

Even if there is a penalty clause, with a 10-day notice clause, you have until the 13th or from the date of written notice. Another problem you face is that once you were 'notified', albeit verbally, you have a responsibility to inform the contracting party of the terms of the contract and give them an opportunity to notify you per the terms of the contract.

At this point, it's time to either contact an attorney and allow him/her to read the contract and advise you further, or contact the company and work out an exit strategy.