Can I connect my personal account to add funds to business account without messing everything up?

I appreciate you sharing a detailed input of your concern, Elephont. I'm here to provide information when integrating a personal account to add funds to your business transactions.

In QuickBooks, it's not recommended to mix your business and personal expenditures to keep your financial data accurate. The accounts you want to connect should be for business-only purposes to avoid confusion when tracking the income and expenses of your company's finances.

With that, you're right. You may connect your bank to your QBO file and only exclude the transactions in your personal account without affecting those transfers to your business account. Once linked, QuickBooks sends downloaded entries to the For Review tab, and then you can start categorizing them manually.

To help you streamline the process, you can create bank rules that automatically categorize them for you. Here's how:

1. Go to the Gear icon and select Rules. Then, click New rule.
2. Enter a name in the What do you want to call this rule? field.
3. From the Apply this to transactions that are ▼ dropdown, select Money in or Money out.
4. From the in ▼ dropdown, choose a bank or credit card account, or select All bank accounts.
5. Set the rule conditions. You can set a single rule with up to 5 conditions. Set and include the following, then select + Add a condition.
6. In the Conditions fields, specify whether the rule applies to Description, Bank text, or Amount. Then select Contains, Doesn't contain, or Is exactly to decide how QuickBooks applies the rules.
7. Select the settings for the rule. Enter the Transaction type, Category, Tags, and the Payee to apply.
8. Once done, select Save.

You can read this resource for additional guidance: Set up bank rules to categorize online banking transactions in QuickBooks Online.

Once everything comes in handy in the future, you can start reconciling your accounts to make sure they always match your bank and credit card statements.

I'm all ears to any additional queries you may have when managing accounts and transactions in QuickBooks. You can always reply to this post, and I'll be around to get you covered. Take care and have a good one!

@Elephont 

I don't recommend to connect your personal account to QB. You have an easy way to reimburse your business expense to your personal account instead.