In the rare instances when your tenants do cost you an unexpected arm-and-a-leg for a plumbing or sewer bill, you'll find that they generally don't have the money to reimburse you for the expense and it ends up costing you a turnover...You can absolutely amend your leases to require the tenants pay a percentage (in this case 1/4) of the utilities.

If your CPA has not explained it well enough to you, you may want to talk with a CPA this year and not wait, even if you already filed (you can always amend).  

Do you have to pay to amend it?

Would amending the contract delay underwriting and closing? 

Good info here, but wanted to add if your building is on higher ground, research the process for a LOMA, letter of map amendment, that may change your status.  

Declaration of Covenants, Conditions and Restrictions (CC&R’s) aka Declarations, or Master Deed.Signed Bylaws for HOAArticles of Incorporation for HOAManagement Agreement (unless self managed)HOA BudgetCurrent Financial Statements (Income Statement & Balance Sheet)Minutes of last 2 HOA MeetingsRecorded Amendments for annexationPlat Map and/or Air Lot Survey Condominium PlansThe process is about 90 days but I think they have a rush fee for about $1000.  

Owner can amend the plan as they go. 

Jim - if you're ever in a pinch, another solution is to form an entity using a simple form LLC agreement for closing and at a later date amend it as the owners require.

Never too late operating agreements are amended all the time but are created at inception of the LLC

Therefore, an amendment to the plat would need to be recorded.