By putting in expenses what do I put in the 'How did you pay' field if I used my personal cebit card (seeing as my business account is not yet set up)?

You can select the account where the money was taken, @useraheadconsultancy.

I'll guide with the whole process in recording expense using your personal card in QuickBooks Online (QBO).

Since this is a personal card, you'll need to record this using Journal Entry first, then reimburse it to an expense.

Here's how: 

1. Go to the + New menu, then choose Journal entry.
2. On the first line, select the expense account for the purchase.
3.  In the Debits column, enter the purchase amount
4. On the second line, pick Partner's equity or Owner's equity. If you don't have it yet, click +Add new.

      5. Re-type the purchase amount in the Credits column.

      6. Tap Save and close.

To record the reimbursement as an expense, please follow the steps below. 

1. Select + New, then choose Expense. 
2. Pick a bank account to use to reimburse the personal funds.
3. In the category column, elect the partner's equity or owner's equity.
4. Enter the amount of the reimbursement.
5. Tap Save and close.

For more information about the process, visit this article: Pay for business expenses with personal funds.

I'd also share with you the steps on how to add business accounts in QuickBooks Online: Connect bank and credit card accounts. 

Additionally, please browse through this article about managing your transactions, deposits, vendors, and other similar topics. 

• Banking
• Expense and vendors

Let me know if you have questions by leaving a message below. I'm glad to help. Take care!

Thank you.  Very clearly explained

I have put in the amount in the debit column and then tried to put the same amount in the credit column and it disappears from the debit column (and vice versa).

When I try to save it comes up a 'somthings not right' error saying 'please balance debits and credits'

Any solution for this?