Start with the Facts:
This was done affecting a credit card. You will use Credit Card Charge, then, to see an increase to the card's running balance. It is Not An Expense entry for the entity paying on behalf of another. It is a Loan to the other entity. Use an Other Asset account, not an Expense account. You don't want this on your P&L; it isn't Yours. Your money and credit are your Assets or Resources made available to you. You let someone else "use your asset" = Other Asset. Other asset = you will be Repaid.
The entity that really should have paid, is incurring whatever this Really is for them. Expense, or perhaps a new computer was purchased = new fixed asset. This Expenditure on their behalf is still Theirs. You enter it as such, but need to show it was "paid by another, on my behalf, and Now I have a Liability to repay them."
That means, for instance, use a Bill for the real vendor name and list what was bought. Use a Vendor Credit to list the Liability account. Apply them to each other using Pay Bills.
Or, use a Petty Cash or Clearing Bank account. "Buy" what you owe for, from this account. "Deposit" funds to this account as Liability, to show you Borrowed what got spent. The net = 0.
But you must ask your own CPA. This type of Commingling, whether inadvertent or intentional, must be handled properly per the Tax rules. Example: Both entities are a Sole Proprietorship = you cannot be in debt to yourself. That means both events are Equity events. Or, one entity has Other partners or members to take into consideration.
