What should I do if the due amount shown online on the IRS website is different than the one stated in a LTR 0474C note from the IRS?

[jessica-burgio77]

I filed my taxes, and incorrectly claimed my child as dependent, when it was her dad's year to claim her.
I then filed and amendment, and made a payment as calculated through TurboTax.
Then I received an LTR 0474C note from the IRS, saying that they found an error in my amendment, and I owed additional X amount.
My IRS online account shows a different due amount. I know that the online account sometimes it's not up to date, but it's been a month, and it still doesn't match the amount in the letter. I made a partial payment, and this is now reflected on the online IRS account, but the total is still different from the note.
I don't know how much I owe. What is the accurate amount I need to pay and be done, the one online, or the one in the letter?

[fanfare]

Your online account is supposed to tell you your current balance.

the fact that a recent payment is shown further confirms that.

@jessica-burgio77 

[jessica-burgio77]

The payment was made online. It makes sense that it shows. I guess I will wait for their reply.

[fanfare]

If the IRS sent you a letter, they are waiting for your reply.

After some time a second more stern letter will be sent.

@jessica-burgio77 

[jessica-burgio77]

I did reply. I also made a first payment. All I'm trying to figure out is how much my balance is, because of the conflicting info.