QB Issue Resolution:

“both have installment payments set up with the IRS to pay down whats owed for 2015 tax year.”

Unless this is a C Corp, those are Personal Debt arrangements.

“I need to show my payments bringing down their balances until paid in full.”

“Their” balances are not going to be tracked in the Business Bookkeeping, because the Business is not liable for Personal Income taxes.

“Not sure if I should be setting it up as a credit account type and treat it as that, or if i should go about differently. please remember I am new to the accountant world. thanks!”

They are using business funds for personal; no matter what they are using it for, the same rules still apply.

This is either Loan to Member, Owed from Partner, or it might be Equity Draw.

You need to work with a CPA for this, if you are not certain.

Resolution for Issue 'how can I register the owner installment payments for prior tax yr 2015, so that the payments that are made thru the company, can reflect the account its paying down on?' available: Yes (Solved).
Source: Intuit Community forum.

how can I register the owner installment payments for prior tax yr 2015, so that the payments that are made thru the company, can reflect the account its paying down on?: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for balances
Quickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!

Error Recovery for balances [Canada]
E-Tech is the #1 Quickbooks data migration and Conversion service provider.

Get 50% off Quickbooks Online

Click Here for 50% off!

Additional Support Options: