Step-By-Step Guide for a Google Sheets Invoice with Automatic Numbering

We recommend reviewing this step-by-step guide carefully to ensure that you don’t miss any steps when setting up the Google Sheets Invoice with Automatic Numbering.

STEP 1. INITIAL LAUNCH AND SCRIPT AUTHORIZATION

After opening the spreadsheet, the first step is to run the script and grant it the required permissions. Do not worry. This is a standard Google authorization process that only needs to be completed once.

Go to the Invoice Template tab and select Invoice → Create New. An authorization dialog box will appear. Click OK to continue.

Next, Google will open a warning window stating “Google hasn’t verified this app.” This message appears for any script that has not been verified in the Google Marketplace. However, this is completely normal. The script is part of your personal copy of the spreadsheet, and no one else has access to it. Click Advanced, then select Go to Automatic Invoice Template (unsafe) to continue.

On the next screen, Google will display a list of permissions requested by the script. These permissions are required for the template to function properly:

Gmail: automatically sends invoices to the client’s email
Google Drive: creates folders and stores PDF copies of each invoice
Google Sheets: generates a new invoice from the template and updates the invoice register

Click Select All, then click Continue to confirm the permissions. The script will now be fully ready to use, and you will not need to complete the authorization again.

STEP 2. SYSTEM SETUP

Now you need to configure the general settings for your future invoices. Go to the Configuration tab to set the main parameters.

Main Settings (Invoice Settings)

Enter Tax Rate %

The default value is set to 0%, but you can change it according to your needs. If no tax is required, simply keep the value at 0.

This value is used in the invoice to calculate tax based on the amount before tax. The amount without tax is displayed in the Subtotal row, while the final total already includes the tax, provided that the corresponding value is specified in the settings sheet.

Payment Period (Days):

You can set any value that is convenient for you. The standard payment period is usually 30 days, but you can change it if needed, for example to 7 days or any other number of days. If payment is due on the same day the invoice is issued, set the value to 0.

Last Invoice (Last Invoice Number):

Leave this field unchanged—it automatically pulls the value from the invoice. Initially, it’s zero, but with each new invoice, the number will increase by one.

Please note: This field accepts numbers only. Alphanumeric entries are not supported.

Next Invoice Number:

This field displays the number of the next invoice.

Currency and Date Format

Date Format:

Select your preferred date display format from the list:

Day / Month / Year – for example, 21/06/2028
Month / Day / Year – for example, 06/21/2028

Currency:

Select the desired currency from the drop-down menu. The corresponding symbol will automatically appear on all invoices.

Currency Symbol:

Currency Symbol: $, €, £, ₴
Automatically applied to invoices.

IMPORTANT: After changing the currency or date format:

A message will appear: “Click button to save format”
Click the “Save Settings” button to save your changes.

Email Settings

Internal Copy Email:

Enter your email address here if you want to receive a copy of every invoice sent. If you do not need a copy, simply leave this field blank.

Email Subject:

Here you can change the subject line of the email that will be sent to the client. The date will be automatically added to the end of the subject, for example:

Invoice from Company Name 19/02/2028

Email Body:

In this field, you can enter the text that will appear in the body of the email. Replace the sample text with your own message according to your needs.

STEP 3. SET UP THE INVOICE TEMPLATE

The Invoice Template tab contains the main invoice template. Fill it out once, and all entered information will automatically be applied to every new invoice you create in the future.

Replace the Logo.

You can replace the image with your own logo or remove the image and leave the cell empty.

To replace it with your logo, select the cell with the image and click Insert → Image → Insert Image in Cell. Then choose an image from your computer.

Invoice Number – after you create and send a new invoice to a client, the invoice number is assigned automatically. The numbering follows the value set in Configuration under the “Last Invoice” field. Each new invoice will use the next number in sequence. No changes are required in this section.

Date of Issue – when you create a new invoice, this field will automatically be set to the current date.

Date Due – this field will be automatically set to the current date plus the Payment Period (Days) value specified in the Configuration tab.

Enter your company or business information.

The remaining fields in the Invoice Template can be left blank and filled in before sending the invoice.

STEP 4. CREATING INVOICES

Creating a Draft

To create a new invoice, select Invoice → Create New from the menu.

A new sheet named “New Invoice 1” will be created. This is a draft version and it will display “DRAFT” instead of an invoice number.

Filling Out the Draft

Some information will be automatically transferred from the Invoice Template that you filled out earlier. All other fields can be completed manually or using the semi-automatic options.

Using the Client Database

In the New Invoice, select a client from the drop-down list. All client details will be filled in automatically.

Managing Clients (Client Database)

Go to the “Client Database” tab to add your customers, clients, or companies. The table already includes a few sample entries. You can use them to explore how it works, then delete them and add your own data.

Enter the company name or the client’s name, and add a contact person if you know it. These details are used in the invoice and in the email greeting. If the contact person is unknown, leave this field blank.

Also be sure to enter the company’s address and email. The invoice will be sent to this email address. If the email field is left blank, the invoice will still be created, but it will not be possible to send it to the company by email.

Table Section. Description of Services / Products

You can add services to the invoice in two ways.

Enter the service name and description manually.
Select from the drop-down list. The items in the list are stored in the “Services” tab. There you can save services that will automatically be available for selection in the invoice.

Calculations

After adding a service or product, select the date, then enter the quantity and price. All calculations will be performed automatically. The system will calculate the service totals and the final amount, including the tax percentage set in the “Configuration” tab.

Multiple Drafts

The system supports working with multiple invoices at the same time:

Work with several invoices in parallel
Send them in any order
Invoice numbers are assigned only when the invoice is sent

STEP 5. SENDING INVOICES

When the invoice is ready to be sent, go to the Invoice menu and select Submit. Please note that this action cannot be undone!

Once confirmed, the invoice will be automatically sent to the selected company’s email as a PDF attachment, and its details will be added to the Transactions sheet.

The New Invoice sheet will be renamed with the corresponding invoice number and saved as a separate line item in the Transactions tab for future use.

Save to Google Drive:

All sent invoices in PDF format are saved to a folder in Google Drive. The system automatically creates the folder path on your Drive. After that, you can find all saved invoices using the following path:

Google Drive → Invoices → 2026 → Invoice 1.pdf

STEP 6. WORKING WITH TRANSACTIONS

The “Transactions” tab is a record of all sent invoices.

When an invoice is sent, certain data is automatically recorded in the “Transactions” sheet. This includes the invoice number, issue date, client, payment due date, gross amount, tax, net amount, and a link to view the generated PDF invoice. Each new invoice is added to the end of the table.

The only column that remains empty is “Payment Date”, which you fill in manually after the invoice has been paid.

At the top of the sheet, above the table, summary information is displayed: the total amount of payments received, outstanding balances, paid and unpaid taxes, as well as the total gross amount (before taxes) and net amount (after taxes).

While the dropdown menu is set to “Select a client”, data for all invoices is displayed without exception. However, you can choose a specific company to view the same metrics only for that company.

Thank you for using our template!

We hope it helps you save time and makes the invoicing process simple and convenient.