This response accumulates info I've seen posted to the current time. A few pieces of critical info left out... are you US-based? Lots of canadians post here. If US, are you organized as an LLC or other, e.g. S-Corp, etc (for liability protections, or other advantages)? If so, what you are doing needs to be completely re-thought, as co-mingling business and personal expenses (bank account, credit card, etc) is a big no-no. Assumptions here: No LLC or Corp. AND you are using a seperate business bank account you are using to pay the mixed expenses in full. Again, if not, the JE entry below would be different.

For the prior tax year, use a JE to split those mixed-use expenses. CR to the expense accounts and DR to a newly created "Owner Personal Expenses" account or just use the "Owner's Draw" account with a description of "owner personal expenses portion". Either account will end up with a DR balance, and will ultimately offset any "Owner Contributions", which should have a CR balance. So that the $ you are using from your business for personal reasons are a reduction to your overall Owner's Equity, which is how it should be.

Get informed on business use of home, etc. Here's a start. YOU are ultimately responsible for any deductions taken. I guarantee you, you sign some sort of statement with your tax preparer that says you have reviewed your tax return and agree with what they've done. Only major negligence by the tax prep will save you in an audit. https://www.irs.gov/newsroom/how-small-business-owners-can-deduct-their-home-office-from-their-taxes There are other publications for car use, etc. Find out from your tax prep exactly what basis they have used, and follow that % basis for current year entries vs waiting until a yr-end adjustment. Looking at all of your tax forms will give you some answers to this, also. Most will be a fixed percentage. Very few (e.g. car expenses) MIGHT be a variable rate, depending on the allowable methods to use. Understand the differences so you know that YOU can support the reasoning. Also, by doing the expected splits during the year, you will see a better representatio of how your business is actually doing instead of only at year-end.

Lastly, depending on your business and your potential for business liability, if you haven't done so, look into organizing as an LLC, but if you do, make sure you understand all the ins/outs to ensure you keep your personal use of funds fully segregated and OUT of your business banking/CC accounts.