Ask any bookkeeper or accountant what the most important first step is in setting up their business finances and books is, 9 times out of 10 (maybe even 10/10) they will tell you to set up a separate bank account just for your business.
Why is this so important?
Well there are three reasons really.
1. For an LLC or Corporation, this keeps your barrier from liability intact.
These business entities set you up for certain protections in the case of your business being sued. Whether or not you maintain that invisible barrier is up to you.
Treating your business like a personal piggy bank is called piercing the veil and it is more than enough reason for you to lose your protection from liability.
2. You aren't perfect; expenses are bound to fall through the cracks.
Sure, you could comb through each personal bank statement five times just to make sure you didn't miss anything, but who's got time for that?
Doing your books this way is a faulty system. There will be breakdowns in the system. Expenses that could be used as tax deductions will be missed.
3. Fixing this in your bookkeeping is a bitch.
For a bookkeeper or accountant it's a piece of cake. For someone who doesn't know the first thing about debits and credits, you can run into some problems.
If it's a personal expense on your business card this will now show up under Owners Draw as though you took your pay.
Instead, go ahead and pay yourself then make that purchase from your personal account.
If it's a business expense on your personal card you have to do either an expense claim if you will be paying yourself back or a journal entry balancing debits and credits...all done manually.
Or you could just not buy personal stuff with your business card...
I've already done this , now what?
Get a business bank account! There are many small banks out there that love small businesses so much they are willing to give you an account for free! Do research and find a good rate. Once you go through the trouble of meeting with the bank and getting your account you are not going to want to do it again when you get tired of paying $15/month for an account. Trust me, I know!
If your entire business is online, a virtual bank might be a good option for you.
Whichever route you decide, check out this list from Nerd Wallet with banks who offer free business accounts by state.