My partner and I started LLC business in August 2015. We didn't file taxes then and want to know if we can combine taxes for both years while filing for this year (2016)?

The obvious two questions that need answering in order to even start to address this quagmire:
1.   Did you actually start operations on or after August, 2015, but in 2015?  Or did you only undertake start-up expenditures?
2.   Did you receive any revenue - gross income - in 2015?

1. We started operations at the end of 2015!
2. We started getting paid in 2015 but our start up expenses were way higher than our income!

The short answer is that you will highly benefit from a tax professional.  Assuming you are filing a calendar-year tax return, your late tax return for 2015 has already accrued at least $4680 in late penalties, plus interest.  While it is possible you may be able to get the waived, that just shows the importance of going to a tax professional to learn how to operate your business.

@TaxGuyBill  - Right on, and one wonders why folks go ahead and start a business, particularly a technology-based business without a proper accounting and tax reporting system in place - only leads to major trouble when not.

We are getting our tax professional involved into this as well after the holidays.
Even if we do not owe anything to the IRS in 2015, they would still penalize us? We will get it cleared up with our accountant but it seems highly unlikely.

Yes, if the Partnership had ANY income or deductible expenses, it is required to file a tax return and the late penalty applies for not filing it.  However, as I mentioned before, your accountant may be able to try to get it waived.

I agree with TGB in that consulting with a tax professional would be a good idea to get you started in the right direction from a tax perspective.  The following will help you understand how all this works:

• Your LLC is a multi-member entity and under the default classification rules will be taxed as a partnership.  This means that the LLC needs to file Form 1065 and provide each member with a Schedule K-1.
• While the form 1065 is informational, the schedule K-1 is what each member uses in preparing their personal tax return.
• At this point, you are late on filing the entity 2015 form 1065 and schedule K-1 for each member.
• Each member's form 1040 for 2015 will need to be amended to include the Schedule K-1 information.
• The form 1065 needs to be prepared and submitted to the IRS regardless of whether the entity has a profit or loss.
• Finally, an even more complicated issue will be the impact of what is known as "click-through nexus".  You need to have someone that understands this provide you with some direction.  States are getting more sophisticated and in need of sales tax and are getting more aggressive in their pursuit to add to the bottom line (or at least less negative).

Thank you for a very detailed response!