This article addresses the process of formatting and uploading an existing lead list into the Overpass platform. For an overview of this subject and information on obtaining leads, please see Client's Intro to Lead Lists.

Accepted File Types

Lead lists must be in a spreadsheet. Accepted file types include:

  • CSV (Comma-separated values)

  • XLSX (Microsoft Excel workbook)

  • XLSM (Excel Macro-enabled workbook)

  • XLS (Excel workbook pre-2007)

If you don't have access to Excel, we recommend using Google Sheets to format your contacts. Google Sheets is free, can handle data from a variety of sources, and allows you to save files in the CSV format.

Row 1 is for Headers / Labels

Row 1, the uppermost row of your spreadsheet, must contain headers/labels which describe the type of data in that column.

Example of correct Row 1 formatting:

Visual example of correctly-formatted Overpass lead list.

Do not use Row 1 for a title, a blank space, or anything besides header labels.

The below examples are incorrectly formatted and will cause errors:

Visual examples of incorrectly-formatted Overpass lead lists (empty Row 1, empty Column 1)

Contact Name Requirements

Leads can be uploaded with just a few data points, or with a great deal of additional information and fields. However, each individual lead added the Overpass system must contain a primary "Name" field, to identify the customer or business.

On your leads list, this "Name" field may be formatted in any of the following ways:

Company Name (single column)

Full Name (single column)

First Name, Last Name (two separate columns)

You may include more than one of these column types -- for instance, many sheets have both a "Company Name" and "Full Name" column. However, only one of these columns will serve as the "primary" name, and this column cannot contain blank rows. For instance, if you have a business name for every entry on your sheet, but only have first & last names for some of them, you'll choose Company Name to be the primary "Name" field, and categorize the other columns as "Text/Numeric" data fields. (More on this process below).

If you currently have separate columns for "First Name" and "Last Name," but some are missing (i.e., you have some rows with only a first name), we recommend combining these two columns into a single "Full Name" column for better results. You can do this using the "&" function as described here.

Please note that you do not need to use these literal titles on your original spreadsheet. During the upload process, you will have the ability to assign a "header type" to each column, so that Overpass knows what type of data it contains. For example, in the below image, this original spreadsheet contained a field entitled "Customer Name." The drop-down menu allows you to select that this column is acting as the Full Name requirement.

Phone Number Formatting

In order for a contact to be dialed through the Overpass platform, valid phone number must appear in that row of your spreadsheet.

Contacts which do not include a phone number may still be uploaded into the CRM, but agents will only be able to contact them through email (if available). If the phone number is obtained later in the campaign, that data can be easily added to their contact record in the CRM, after which they can be dialed.

Acceptable formatting for phone numbers includes:



no spaces or punctuation


digits separated by hyphens


digits separated by spaces

333 444 5555

area code in parentheses, hyphens

(333) 444-5555

(Numbers do not all need to follow the same format; your lead list may contain a mix of the above options.)

The country code (+1) may be added in front of any of the above formats without issue (for example, (+1) 333-444-5555) but this is not necessary. Please note that at present, Overpass can only be used to dial numbers on the U.S./Canadian numbering plan. International numbers cannot be uploaded.

Unacceptable formatting includes:



digits separated by periods


any type of leading letter or word

(C) 333-444-5555

leading country codes (besides +1)

(+44) 333 444 5555

numbers with extensions

333-444-5555 ext 100

Extensions should not be included in the same cell as the rest of the phone number. Please use a separate column to list this information, as shown below. (The extension will not be dialed as part of the initial call, but the agent will be able to see this information and enter it during the call.)

Example of using a separate column to store phone extensions

How Much Information Can A Single Lead Contain?

Besides the minimum requirements, your lead sheet may contain as many additional columns/fields as you like. These fields may contain data or be left blank for your agents to fill in later. (For example, if you don't currently have any email addresses, but hope to obtain that information during the calling campaign, simply add a blank column with the header Email.) Any totally-blank columns should be kept to the right of all "populated" columns.

Example of a lead list with blank columns shifted to right.

There is no limit to how many columns your lead sheet may contain. Additionally, the order of these columns does not matter (with the exception that blank columns should be kept to the right.)

Additional Phone Number Columns

Of course, some contacts may have multiple phone numbers connected with them -- for example, an office line and a cell phone. Lead lists with more than one "Phone Number" column are fine, but remember that only one column will serve as the primary phone number, and as discussed above, this column cannot contain gaps or blanks. Additional phone number columns may contain blanks without issue:

Example of multiple phone number columns correctly formatted.

If your lead list contains more than one phone number column, the site will ask you to identify which is the primary phone number. Be sure to select a column which does not contain gaps or blanks.

Pop-up message prompting user to select primary phone number column.

Verifying Headers

When you upload a new list, Overpass attempts to identify what type of data is contained in each column. Generally these initial labels will be accurate, but be sure to double-check, as mistakes can happen.

For instance, some lead lists may contain a "Customer ID" or "Account #" column which may be read as a phone number. In the below screenshot, the site has mis-identified the Customer ID column as containing phone number data:


Fortunately, this is easily resolved: just use the drop-down menu to select Text/Numeric as the data type:

Example: Changing a column header.

After you've verified that all labels are correct, just click Done Verifying Headers.

Options For Handling Duplicate Contacts

When you upload fresh leads, our system compares the phone numbers in your new list to the rest of your workspace, to check if those numbers appear in any other lists or campaigns already. Note that a duplicate is defined as a contact with the identical name and phone number (and/or name and email address).

Note that contacts which share a phone number (such as a corporate/master number) but have different names are not considered duplicates and can all be uploaded.

There are two different methods for handling duplicates.

Overwrite Existing Contacts means that if your new lead list contains a record which is a duplicate of a record that already exists in the system, we will use the new information to overwrite the old record. (This is useful if you have a new lead list which contains some of the same names, but is generally more detailed or more recently updated than your existing data.)

Please note that overwriting does not affect any outcomes associated with the number -- for example, if a lead has already been marked as "Not Interested," overwriting with alternate data does not remove that outcome.

Keep Existing Contacts means that if a duplicate number is identified, we will use the original information that already exists in the CRM, and ignore the new data. (This is useful if you have a new lead list that contains some new names but some old name as well, and you do not wish to overwrite any of your existing information.)

Still stuck? We know that uploading a lead list can sometimes be a bit tricky, especially depending on the state of your current data. If you need additional assistance, please don't hesitate to email your specific lead list file to and we can help get it uploaded for you.

Did this answer your question?