Our LLC started in November 2015. Me and my partner invested $7000 each. In 2016 we reported $2888 total net loss. What would be our beg. capital balance for 2017?

If you had no other items that affect Partners' capital accounts, the Beg. Capital Balance for 2017 would be $11,112 ($14,000 minus $2,888).  Each partner's beginning basis would be $5,556.  

Make sure you have taken into account all the items that affect basis.

Besides the partner's distributive share of taxable and nontaxable partnership income(loss) they include:

• Additional cash and property contributions
• Distributions of cash and property
• Non deductible partnership expenses 
• An increased or decreased share of, or assumption of, partnership liabilities. 
  
• Depletion of oil and gas.

Click here on this link for more information from IRS Publication 541: https://www.irs.gov/pub/irs-pdf/p541.pdf