If I cancel my quickbooks subscription, in order to start new/reset my account, will it also cancel my merchant account / force me to get a new merchant ID and all that?

Welcome to the Community, @billing60.

Your merchant account won't get cut if you choose to cancel your QuickBooks Online (QBO) account. Aside from canceling, you may also consider purging your QBO to clean slate. I'd be glad to discuss this in detail and guide you in getting things done.

Purging allows you to delete all your QBO information so you can use the same account and start fresh if you're still in the first 60 days of using it. Know that this process works for all Plus and Essentials versions only. If you're ready, please follow these steps on how to purge your account:

Here's how to purge the data: 

1. Log in to your QuickBooks Online account.
2. Look at the URL in your address bar and change all the text after the last " / " with purgecompany. Example: https://...qbo.intuit.com/app/purgecompany
3. Type the word “YES” to agree, then click OK.
4. Hit Wipe Data.

But if you prefer canceling your QBO account, you can follow these steps:

To cancel your account:

1. Go to the Gear icon and choose Account and Settings.
2. Select the Billing & Subscription tab.
3. In the QuickBooks section, click Cancel Subscription or Cancel Online.
4. Select Continue to cancel.
5. Follow the next steps.
6. Click Submit and cancel subscription.
7. Hit Got it.

To resubscribe:

1. Go to https://quickbooks.intuit.com/choose-country/.
2. You can enter the same login credentials.
3. Go back to the Billing & Subscription page.
4. Click the Resubscribe button.

If you have other concerns, please let us know. Have a great day.

@billing60 

If you have to open a new QBO account, make sure to click the Buy button to get the discounted price for up to 6 months. If you purchase from the trial account, you have to pay the regular price.

https://quickbooks.grsm.io/US

https://quickbooks.grsm.io/us-promo