So we have a husband/wife partnership passthrough LLC, we are taking w2 from this LLC, We open a 401k Solo account in Dec 2018 so to establish 401k in 2018. Now we know that we can do deduction and contribution (18500 + 25% of compensation @ maximum of 58000 approx) prior to the tax deadline. My question is 1) Can we deposit only employer contribution to 401k or we have to have deposit our deduction to have the contribution. 2) How to record this contribution in QBO so to have this expense out.  I know because this is passthrough I can Draw and report this directly to 1040. Now 2018 has gone can we do some adjustment to record employer contribution. Thanks for all the help.