I appreciate you for bringing this to our attention, @mushmorris. Let me help you change your phone number in your QuickBooks Online (QBO) account.

For security reasons, only you can modify your Intuit account. Our support team cannot access or make changes to your account details.

Since you no longer have access to your phone number on file, we'll need to verify your identity before we can approve your request to update your account details. Please refer to these steps:

1. Take a high-quality photo or scan of your driver's license, state ID, passport, or notarized document.
2. Fill out the form with your info, and upload your ID or document. To access it, please go to the Proof of Identity section in this link: Recover your Intuit Account if you can’t sign in.
3. Within one business day, look for an email from no_response@intuit.com with the next steps. 

Once done, you can change or add a phone number to your account, so you can receive verification codes from us for future sign-in attempts.

Furthermore, QBO offers dozens of reports to help you obtain an overview of your business. This way, you'll be able to see how your sales and expenses are performing.

Please know that the Community is open around the clock whenever you have any follow-up concerns about updating your phone number. Just mention me in your reply, and I'll sprint back into action. Stay safe and have a wonderful day ahead!

None of the pre set problems are helping me with my issue. 

Getting code 5008 and a declined credit card.  Which in my understanding is a wrong card number.  This is incorrect because the card number is correct along with the date, name and three digit code.  We have processed this payment in the past for our customer and it is frustrating that it is declined.   They have tried too on our link to pay and have been declined too.   We need to get this fixed.  It is delaying our company of getting paid promptly.    Sherry [last name removed] [phone number removed].

Thanks for getting involved with this thread, 5008. I appreciate your detailed information.

When a customer's credit card is declined, they can contact their card issuer and confirm the exact reason why they chose to decline their transaction from taking place. There's a series of reasons a decline can occur.

Here's some things you can check:
 

• Use your customer's address from the US USPS website.
• Confirm there's no special characters or spaces in any data fields while entering their card details.
• Make sure the card number is correct. Most card numbers are 16 digits long. American Express cards are 15 digits long.
• In addition to the card number, you need to enter a verification code. For most cards, like Visa, Mastercard, and Discover, their cards have three digit codes on their backsides. For American Express, it's a 4 digit code on the front of your customer's card.

If you're trying to process a business credit card, for example, some of these cards require additional commercial codes to process transactions successfully. You can get in touch with your Customer and ask them to verify if their employer requires a special commercial code for purchases.

In the event your customers need to use special commercial codes for their credit cards, go to the Merchant Service Center and update your industry type. This will enable the account to process commercial codes.

Here's how to update your industry type:
 

1. Sign in to the Merchant Service Center.
2. From your top menu bar, go to Account, then Account Profile.
3. In the Account Holder/Business Information section, click Edit.
4. Enter your last for digits of the business's Tax ID number, or your SSN.
5. Hit Submit.
6. Choose an appropriate Industry Type.
7. Specify a Reason for this account change.
8. Select Submit.

You can also check your transaction log in the Merchant Service Center, under Activity & Reports, to verify a transaction's status and other information about declined, approved, or pending transactions.

If you need to process flex spending (FSA) cards, you can review our Accept flexible spending cards article.

I've also included a detailed resource about working with declined credit card transactions which may come in handy moving forward: Fix customer's declined credit card payments

I'll be here to help if there's any questions. Have an awesome Monday!