# Manual Sync Configuration Update

You can add/update/remove tables and fields to your existing syncs from the Stacksync dashboard. Here is a [quick video on how to update sync config for HubSpot](https://docs.stacksync.com/guides/add-a-new-custom-field-to-an-existing-sync).

<details>

<summary>Adding a new column in an existing sync: Explaining automatic data backfill for existing records.</summary>

The sync configuration update is a smart feature. For example, when you add a new column, all the data of that new column will backfill for the already synced records (historical data backfill), and keep syncing incrementally for any new update in real-time.

![](https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FPzVDnlCWTpDhnYGmOdRT%2Fimage.png?alt=media\&token=5411b9e5-7d1a-42e6-ab7a-fe8b8402cc6c)

</details>

Updating a sync can be done in simple steps. Here is how:

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FwtsHlxigHmJgyAHSj6Ro%2FUpdate%20Sync%20Configuration.jpg?alt=media&#x26;token=30c5a140-e8fe-4fa6-85cf-a8f6a93bbb09" alt=""><figcaption><p>Update your Sync configuration GIF Guide</p></figcaption></figure>

## Step 1: Pause your sync

If your data keeps syncing while you modify your schema, table or column names/types in one of your synced apps, this could impact data in your other app in sync. This is why pausing the sync ensures maximum comfort for your sensible manipulations.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2F21Vc0sRqbYG3uzsVzkbW%2F1%20(1).png?alt=media&#x26;token=48d28f66-7958-44ef-b2e2-ae35fc5cc35b" alt=""><figcaption><p>Pause your Sync (Switch OFF)</p></figcaption></figure>

## Step 2: Modify your schema, table or column names/types in your external apps

Now you can do any modification you would like, feel free!

{% hint style="success" %}
All modifications are allowed, no limits!
{% endhint %}

## Step 3: Update your sync configuration

In your dashboard, open the sync details of the sync impacted by your changes.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FKDN8BzifpHjoAYeO5RAW%2F2%20(1).png?alt=media&#x26;token=962e11d9-db4c-4eb8-9fcd-5a8ad9fa76d2" alt=""><figcaption><p>Open Sync details</p></figcaption></figure>

Click "Edit Sync" and follow the guided steps.

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FrKK5ZSnbIVC2rbCGb5IZ%2F3%20(2).png?alt=media&#x26;token=0b0b9b1c-0bf5-4a1f-82e3-bb653c672a77" alt=""><figcaption><p>Start Editing Sync</p></figcaption></figure>

This process is very similar to the [sync creation process](https://docs.stacksync.com/two-way-sync/start-here/quick-start) (reauthorize apps if necessary, map tables and fields) but with additional features that enable you to keep going from where you left off! 🪄&#x20;

## Step 4: Confirm your changes

{% hint style="danger" %}
Modifications to sync configuration are not reversible. Double-check your new configuration before validating!
{% endhint %}

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2FtTle85ffabC3Mugn4BBQ%2F4.png?alt=media&#x26;token=d004bb5a-0e0d-46aa-b053-3d28139fe11d" alt=""><figcaption><p>Save your Sync edits</p></figcaption></figure>

## Step 5: Turn sync on!

<figure><img src="https://2867423571-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FfJjIdV9cuW6K8asJjTPJ%2Fuploads%2Fh2RgG80ZGOr6mqzgnlVf%2F5.png?alt=media&#x26;token=e31419c3-ba7f-47cf-8476-f74367a135a1" alt=""><figcaption><p>Turn sync on and data starts syncing between your apps!</p></figcaption></figure>

That's it! 🎉 Data will start syncing between your tools.