How can I change the company address? Since my phone number is Mexican it assumed I am based in Mexico, when the company is US company. Now all the currency is in MXN

You're in the right place, Antonia. I'm here to ensure you can update your company address in QuickBooks Online (QBO) to its correct location. Allow me to lend a hand in accomplishing this.

Before we start, please know that your country is determined by the regional website where the subscription was created. As a result, your location's address and currency will be based on that area.

For reference, please read this article: Can I change the account's country?

It is important to ensure that your company's address is correct because it affects customer contact and communication. To successfully update your company's address to the correct location, please follow the steps below:

1. Head to the Gear icon, then Accounts and settings.
2. Go to the Company, then click the pencil icon from the Address section.
3. Enter the address in the Company address field.
4. Select how your customers can contact you from the Customer-facing address field.
5. Input the location you use when filling out your taxes
6. Once you've ensured that everything is correct, click Save, then Done.

See this article for reference and additional details: Change your company name, contact info, or Business ID No in QuickBooks Online.

Additionally, updating your company address doesn't guarantee a change in currency. To select the correct one, you'll need to manually edit it from your account. To do so, here's how:

1. In your upper right corner, go to the Gear icon.
2. Select Account and Settings, then Advanced tab.
3. Select the Currency section and click the pencil icon. 
4. Choose the correct Home Currency from the dropdown.
5. Hit the Save button. Then Done.

If the multicurrency feature is turned on, changing your home currency won't be possible. In that case, you'll need to reset your QBO files from the beginning to use a new one.

For reference and additional information, please visit this article: Delete your data and start over in QuickBooks Online

If you want to add people to your account, please read this helpful article for guidance: Add and manage users in QuickBooks Online.

Don't hesitate to reply to this post if you need help changing your company address. The Community space is always available for you.