How To Clean Contact Lists For Precise Targeting

Published on April 29, 2024

Why do clean contact lists matter?

A list-building exercise typically involves inbound marketing techniques such as SMS opt-ins, web forms, and custom bots. Sometimes, you need to purchase contact lists to begin your outreach process and need clarification on their quality and accuracy.

Therefore, campaigns must take extensive measures to vet contact lists before they begin and maintain clean contact lists periodically. This means that you remove unengaged, unsubscribed, invalid, or duplicate contacts from time to time.

This article explores how you can maintain clean contact lists and steps you can take on CallHub to ensure your lists are sparkly clean.

Why are clean contact lists necessary?

Apart from the fact that sometimes campaigns do not know the quality of their list of contact numbers, here are some crucial numbers to consider:

  1. Communication platforms typically set a 10% error limit to texting campaigns.
  2. They have a 1% opt-out limit. You risk account suspension if you bypass these limits regularly.
  3. The average call duration for calling campaigns must be <20 seconds, and the unanswered call rate must be below 40%.
  4. A clean list costs you fewer dollars per campaign (since irrelevant numbers will be eliminated).
  5. It improves your delivery, answer, and response rate (even if the number of calls or messages decreases).

Manual inspection of numbers is tedious and time-consuming for campaigns with an exhaustive list of contacts. But that’s what we’re here for—to help you do the tedious job so you can focus on the campaign.

There are three types of numbers you must remove from a list:

  • Bad numbers (to reduce error rate).
  • Unresponsive numbers (consistent busy tone/machine answer/canceling OR no text replies).
  • Unreachable numbers (for reasons other than bad numbers. E.g., landline number in a texting campaign).

Let’s look at how to do it on CallHub.

How to get clean contact lists

Before we begin, let’s define the various types of numbers that make a contact list messy. In the most basic terms, numbers that don’t receive or respond to your communications show unsatisfactory engagement and make your list messy. On the other hand, numbers that take the action you desire regularly enhance the quality of your list.s

How do you figure one from the other?

  • Calling campaigns: After every call, the agent can manually assign statuses such as congestion, originator cancel, busy, failed, etc., which are reflected in your calling reports. The agent also manually adds dispositions such as DNC, which is reflected in your reports, and the DNC list on CallHub (which comprises all numbers that do not want to be contacted, irrespective of the campaign). Call drop statuses will be added automatically.
  • Text campaigns: For texts, the tool marks the status of a sent message. Undelivered texts, bad numbers, gateway errors, etc., should be reflected on these statuses to help you understand how well your text campaign is going.

Here are the types of contacts that require review or elimination from your list: 

  1. Bad numbers: These are incomplete or non-existent numbers.
  2. Unallocated number: Numbers that are not allocated or registered to a person.
  3. Failed:  These are unreachable numbers.
  4. Disposition- Do Not Call: The contact requested that you not contact them again.

CallHub automatically eliminates numbers allocated to the DNC disposition from your calling and texting campaigns. Your account’s DNC list automatically adds these numbers (you can also manually add contacts there).

To remove contacts from the DNC list, you can do one of the following:

  1. To remove individual contacts, go to Do Not Call > Search for the number > Click the checkbox > Delete selected from Actions.
  2. To remove contacts from the DNC list in bulk, contact CallHub’s support team – [email protected], who will do it for you.

You must manually weed out the rest. Let’s look at how to do it. 

Cleaning lists for calling campaigns

Your contact list clean-up for calling campaigns includes bad numbers, consistently unresponsive numbers, or those that go to machines or voicemails.

For call list scrubbing, follow these steps:

  1. Log in to your account and go to Reports – Call. 
  2. Filter campaigns by the desired date range or specific name and hit search.
  1. Filter by the relevant preset or custom disposition (e.g., FAILED).
  2. Click on export results. Delete the extra columns and only keep a single column – phone numbers.
  1. Now, go to contact lists > and click on delete contacts. Upload your CSV file here and select the country. Click ‘Delete contacts, ‘ and your contacts will be permanently deleted.
Important Notes:

1. Once you delete contacts, you cannot recover them. Always keep a backup or double-check the lists you are deleting.

2. The tool will only remove contacts that are not part of an active campaign.

3. The contacts will be deleted from your account and not just a contact list.

Read Also: How To Build Your Voter Contact List | by CallHub | Medium 

Clean contact lists for texting campaigns:

The contact list clean-up for texting campaigns involves reviewing and removing permanently unavailable, blocked, or consistently undelivered numbers. 

Suppose your campaigns aim for responses or specific actions from recipients. In that case, you can enhance the list quality by eliminating unresponsive numbers (not responding to any messages or having stopped doing so over time).

Follow these steps to clean lists for texting campaigns:

  1. Log in to your account and go to Reports – Text.
  2. Filter campaigns by date range or a specific name.
  3. Filter further by status Failed, No Route, or Unauthorized. You could filter them by one or all error codes (e.g., 50: Invalid destination number). We recommend filtering particular error codes for a list-cleaning exercise to avoid deleting temporarily unavailable/undeliverable numbers. 
  4. Click on “Export.” Open the file on your computer, delete all columns except the phone number column, and save the file.
  1. Go to contact lists and select “Delete Contacts.” 
  2. Upload this exported and edited file and click “Remove Contacts” to confirm this action.

Again, deleting contacts is a permanent action. We will not be able to recover these contacts for you. Please ensure you have a backup and double-check before deleting contacts.

Read Also: All You Need To Know To Send Automated Text Messages 

Cleaning individual contacts in a list

Bulk deleting contacts is only sometimes the solution. Sometimes, you want to delete just a handful of specific contacts for a clean list, but going through all the above steps doesn’t feel right. 

PS: Merging duplicate records or combining multiple contacts into one household can also keep your list clean and of optimum quality.

Let’s look at how to remove contacts individually:

Removing individual contacts

Go to Contacts. In the search box, Type in the phone or mobile number (this will show all records with the same number). Then, Click on the x mark under Action to delete the contact.


To manually delete multiple contacts at once, press the Control or Command key and select the applicable ones. Then, click the ‘Actions’ button on the top left corner and select ‘Delete Selected.’


Merging two or more contacts

For instances of duplicate contacts (names or numbers).

Go to Contacts – Select one of the contacts you want to merge – Click on the “Merge” button under “Actions” (two arrows going in opposite directions). 


The tool will take you to a different page (the same tab). Select the contact with whom you want to merge the original. Click “Merge.”

Read Also: Your All-In-One Guide To Conversational Text Messaging 

Connecting households for clean contact lists

Households are when several household members share a number (most likely a landline).

Go to Contacts, select one household member, and click the “Contact Household” button under “Actions.”


When directed to the “Household” page, click the “Add” button against the desired household contact.

Try CallHub for free here.

Best practices for building clean contact lists

A list-cleaning exercise is a necessary part of maintaining your list quality. However, doing it retrospectively can be tedious. Once you’ve done the list cleanup, adopt best practices to build new lists that are already (relatively) clean. Here are ways to do that: 

Buy lists from a qualified vendor

Start at the very beginning of building your contact lists. When you purchase from a contact list vendor, ensure that they are well-qualified and reviewed and sell good-quality contact lists.

Here’s why this is so important:

  1. Data accuracy: A qualified data vendor will ensure their data is accurate and up-to-date.
  2. Compliance: Good data vendors ensure compliance with GDPR (General Data Protection Regulation) and other regulatory authorities. You can run your campaigns without worrying about the legality of the data acquired.
  3. Value for money: While these databases might cost you more in the short term, they ensure your campaigns have higher conversion rates, reach the right audience, and avoid wasted resources on poorly targeted campaigns.

At CallHub, we’ve partnered with some trusted vendors like L2 Data, HaystaqDNA, Statara, and TargetSmart that might help you begin your journey. 

Keeping import and export easy

The simplest way is to stick to a CSV (comma-separated values) format when exporting or importing data between different services and systems. Compared to Excel or PDF files, CSV is much easier to migrate between systems. Excel’s auto-formatting often messes up numbers because there is no clear distinction between numerical values and text. As a text file, CSV stores data as is, making it easier to edit manually. It also consumes less memory and makes for faster transfers.

Use integrations

Integrating your different outreach platforms is an excellent way to maintain clean contact lists. If contacts flow easily between two databases, all actions in their contact history are updated. Based on their past interactions with you, you will be completely updated about which contacts are worth keeping and which need to be removed.

If you use CallHub for outreach efforts, integrate it with supporting CRMs such as NationBuilder, NGP VAN, Salesforce, PDI, and Blackbaud. Alternatively, use Zapier for an easy two-way flow of contacts and real-time updated information.

When you update or clean contact lists on one platform, it automatically makes the changes on the other platform, avoiding double the effort.

Maintaining address formats

It is essential to have a distinct field for addresses in your contact list. Keep a strict format for inputting addresses finalizing the format of details such as 

  • House number format
  • Chronology of locality, apartment, street, etc.
  • Spacing between text and numerical.

Street names, districts, and pin codes should be clearly separated and given their own column in case you need to sort by location.

Maintain the date of entries.

There are a few uses for maintaining proper dates for entries in the contact list. You could specify a certain period and choose to reach out to contacts made only during that period. Sorting contacts by dates helps in such cases.

Make sure the date formats are consistent throughout the contact list. Specify DD-MM-YY (highlight the use of hyphens Vs. dashes, YY or YYYY) or MM-DD-YY so your agents can understand the right way to input dates.

Separate name fields

Your contact list should separate name entries by first and last name fields. This is helpful when importing the list to a system that recognizes and sorts names accordingly. Additionally, it makes contacts easily searchable when merging or connecting them to a household.

Maintain order of first and last name for all entries to avoid confusion.

Re-engage contacts before removing them: clean contact lists

Before you begin your phone number list cleanse, there are some actions you can take. While some of your data is unusable due to accuracy errors or opt-outs, you can still salvage some contacts. Run a retargeting campaign that coaxes contacts to re-engage with you. If they still don’t, it is time to remove them from your lists.

Clean contact lists regularly

Schedule a list-cleaning exercise regularly to ensure your lists don’t become outdated as time passes. Schedule a clean list maintenance exercise every month, quarter, or six months at least.

Make unsubscribing or opt-out easy for clean contact lists.

Whether sending texts or making calls, always give your audience the option to opt out. Yes, you might feel that it is counterintuitive to let contacts go, but not only is it legally the best option, but it is also the best way to maximize campaign effectiveness.

Cleansing a sales call list by providing opt-out ensures your communications only reach an engaged audience to make the best use of your money. So, while it may not feel good to see your list go down, understand that the ones who remain on the lists are more likely to take action.

What’s next?

While building your contact list, these small measures will ensure your list is clean and easy to filter and migrate between systems. While a periodic list clean-up is highly recommended, building a well-organized list substantially reduces cleaning time and effort.

At CallHub, we curate high-quality resources to help our audience. If you want to know more about how to maintain clean contact lists, here’s a CallHub webinar in association with L2 data called ‘How To Clean Your Contact Lists’ that you might want to watch:


Featured Image Source: Gustavo Fring