How do we record a prepayment by a customer?

Allow me to guide you to record customer prepayments in QuickBooks Online, userconteh1abdul.

To record the customer prepayment, you’ll need to record a retainer or deposit. This way, the transaction will show correctly in your financial reports. The retainer or deposit will be a liability to show that your business is holding the money but it doesn't belong to you until it's used to pay for services. This liability will then turn into your income.

To start with, create a liability account to track the amount of the retainer you received from your customer. Let me walk you through the steps:

1. Go to the Gear icon at the top.
2. Under Your Company, choose Chart of Accounts.
3. Select New.
4. In the Account Type drop-down, choose Other Current Liabilities.
5. In the Detail Type drop-down, select Trust Accounts - Liabilities.
6. Enter the account’s name or leave the account name as is.
7. Click on Save and Close.

Then, create a retainer item you can use to receive the deposit or retainer from your customer. For the detailed instructions, refer to the steps below:

1. Go to the Gear icon at the top.
2. Under lists, choose Products and Services.
3. Then select New.
4. On the Product/Service information window, select Service.
5. Enter a name for the product or service item.
6. From the Income Account drop-down, choose Trust Liability Account.
7. Click on Save and Close.

Here's an article for the complete details about prepayments: Record a retainer or deposit 

We'll be right here to back you up if you need additional assistance with the process.