Working with duplicate contacts

All you need to know about duplicates and contact merge.

Written by Anthony Green
Updated over a week ago

When contacts are added to groups on your Airship account, we automatically scan for existing contacts that match to make sure duplicate records are not created.

Airship’s automatic merging is how we keep your database clean from duplicate data, without you having to spend time retrospectively removing duplicates.

How does the automatic merging work?

Each time a contact tries to join a group, for example from a signup form on your website, our algorithm will detect if the contact already exists in your Airship account. It does this by checking against two unique pieces of personally identifiable information, firstly the email address and secondly the mobile number of the contact.

For example, if “” tries to join your database, but he already joined a week ago, Airship will identify that this individual already exists, and it will merge their contact record automatically. Each time one of these merges occurs, a record is made of this, so we know the exact date/time each merge occurred.

Here’s another example. If “” also supplied his mobile number when he signed up to your database, we’ll also use that information as part of the automatic merging. This means that if John changes his mobile number in the future, but keeps his email address the same (or vice versa!) then we’ll still be able to identify this individual and maintain their single contact record.

When a contact merge occurs, the transactional data, such as bookings or Wifi interactions, that was associated with the contact record is not transferred to the new contact record. We do this because it ensures that transactional data is not accidentally merged with an individual that it may not belong to. 

Avoid the use of fake data

If technically valid but fake data is added to your Airship account, such as an individual with mobile number 07800000000, contact merging will still occur. This means that any contacts added using inaccurate data will still merge into single records to avoid duplicates.

We recommend that you discourage the use of fake data, ensuring that all data entry points into your Airship account use accurate data to avoid merging issues. Remember, the same applies to fake email addresses too, so a record created with “” would merge with any other contacts created using that email address.

How to assist your customers

If your customers are asking about their contact record, you might want to look deeper into their record history to check when the merging occurred.

  1. Log in to your Airship account.

  2. From the sidebar go to Contacts > Simple Search.

  3. Click ‘Narrow Search by Personal Details’ to enter the individual’s email or mobile number.

  4. Click ‘Search’.

  5. When the search results show, click ‘Edit’ next to the contact record.

  6. On the contact record screen, click ‘View Interactions’. 

  7. Click the arrow underneath 'Merges' to display the merges table.

  8. This table shows the merge history for this contact record.

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