I have clients that pay their bill before service and I still get invoices through quickbooks. I have over 100+ invoices to complete. best and quickest way to complete?

Hello there, touched.

I'm here to guide you in completing your customer invoices.

If you haven't yet recorded the customer payments, you can enter them using the Receive Payment feature and retain them as credit so you can apply them once the invoices are entered in QuickBooks.

Before proceeding, make sure that the automatically applied credits are turned off so the payments won't be applied to the other open invoices of those customers. Here's how:

1. Navigate to the +New menu and select Receive payment.
2. Select the customer's name and enter the amount of the payment in the Amount received field.
3. Choose the account where you want to put the amounts in the Deposit to box.
4. Then, click Save and close and select Save as credit.

For reference, check out this article: Record invoice payments in QuickBooks Online.

Once done, the quickest way to add those 100+ invoices is to manually import them via CSV file. However, this does not automatically apply to the payment recorded in the system. You still have to manually link them. I'll guide you on how:

1. Ready your spreadsheet containing the invoices you need to add. You can download a sample file found in the product to serve as your guide in entering the details needed.
2. Once done, select the Browse button and choose the CSV file containing the information
3. Then, select Next.
4. Map your columns and headings and click Next.
5. Follow the on-screen steps to complete the process.
6. Read this link for more information: Import multiple invoices at once in QuickBooks Online.

When everything is fine, let's apply the payment to the invoices. Here's how:

1. Click the +New menu and select Receive payment.
2. Next, select the customer name in the Customer dropdown.
3. From the Outstanding Transactions section, select the open invoice you want to apply for the payments received earlier.
4. Then, in the Credits section, choose the credits you want to apply.
5. For the open invoice in the Payment column, enter how much of the credit you want to apply.
6. Leave the payment method, reference no, deposit to, and Amount received fields blank.
7. Fill out the rest of the form, including the Payment date.
8. Make sure the total is correct after applying the credit memo.
9. Once done, click Save and close.

If you need help personalizing your invoices, here's an article for more details: Customize invoices, estimates, and sales receipts in QuickBooks Online.

I'd be always here ready to lend a hand if you need further assistance in managing your customer's invoice. Please don't hesitate to leave a reply below. Have a good one.