So you've been using Appcues for a little while, but at some point, you realized that the user IDs you've been sending to Appcues need to change. This can happen for a couple of reasons:

• The IDs were set incorrectly during installation.
• Your developers have decided to change the format of user IDs (e.g. from sequential numbers, like "0001", to a hash, like "a4d93c").
• Products you'd like to integrate with Appcues are receiving different user IDs, and you'd like to standardize.

Whatever the reason, we can help you understand the process and things to consider when making that change.

First, it's important to know that Appcues treats the user ID passed to us (via your installation) as the canonical identifier for your user. If that user ID changes, we consider it a brand new user and do not merge the histories together. This is how we're able to track that users see the right content at the right time and frequency.

Implications of changing the user ID

If you decide to change the user ID passed to Appcues, we will treat them as completely new users. That means:

• Users who have seen a flow, checklist, NPS survey, etc may see it again (if they still qualify).
• You will be unable to target new flows based on behaviors associated with the previous user ID (eg custom events, other flows they've seen).
• User-based stats, like MAU counts, will appear doubled.
• Other stats, like Goals and Segments, may also be counted twice for people meeting those criteria anew.

How to mitigate data inconsistencies

In general, changing user IDs mid-cycle is going to have some kind of drawback. Here are a few options you can take to minimize the above impacts, though potentially at the cost of others.

Avoid duplicate user data:

If data cleanliness is very important to you and you have not created too much content in Appcues yet, you can start a fresh new Appcues account and move your subscription to it. That provides a chance to redo installation and start with a clean slate.

Avoid showing things more than once:

If you have a lot of content and don't mind that long-term views (eg "all time") of your data will be inflated, we recommend taking one of the following steps to avoid showing pre-existing flows to newly identified users:

1. Target existing flows to be shown only to users created after the ID change. This will require sending a Created Date property for users going forward.
2. Unpublish existing flows. This will guarantee no one will see the same thing twice.