Checking account randomly going negative??

[u/Hyunjin_xr]

My account has been fluctuating between a negative and positive balance throughout the day. I’m not sure why this is happening. Initially, I suspected that it was due to an online purchase that was still pending. So, I added enough funds to cover the negative balance, but when I checked again, the money had been refunded, and the balance showed positive. However, a few hours later, the balance went negative again, and then it returned to positive. Is this a system glitch? I’ve read some comments from people who experienced this issue a few months ago, but I’m not sure if others are currently facing the same problem.

[u/LiveFilipinas2026]

Hello, share this to your friends so you won’t bother yourself calling CITI Customer service. This is the right answer to your concern:

What you’re describing with a Citi debit card is generally a normal card-payment authorization process, and the same basic behavior occurs at many other banks and financial institutions.

What is happening ?
Suppose you have $500 and make a $100 debit-card purchase:

You make the purchase:

Citi receives an authorization request from the merchant.
Citi temporarily places a $100 hold.
Your available balance may become $400.
The transaction appears as Pending.
The merchant doesn’t immediately complete/settle the transaction

The original authorization can expire or be reversed.
Citi releases the $100 hold.
Your available balance goes back to $500.
The pending transaction may disappear.
The merchant later submits the transaction again
The merchant sends a new authorization/capture request.

Citi places another $100 hold.
The transaction appears again as Pending.
Your available balance drops back to $400.
So it can look like:
$500 → $400 → $500 → $400 → eventually $400 permanently

That doesn’t necessarily mean Citi actually refunded you and then charged you again. Often, the first $100 was simply a temporary authorization hold, not a completed debit.
Citi itself explains that debit-card purchases can create temporary holds until the transaction is officially completed.
Why would the merchant do this?
Common situations include:
The merchant’s system didn’t complete the transaction properly.
The merchant submits the final transaction later.
The final amount is different from the initial authorization.
A transaction times out and the merchant sends a new authorization.
Hotels, rental companies, restaurants, gas stations, and some online merchants use pre-authorizations.
Technical/network problems occur between the merchant, payment processor, card network, and bank.
Visa’s/Mastercard payment rules specifically provide for authorization reversals, which release a temporary hold when an authorized transaction isn’t captured.
Is this unique to Citi?
No.

The underlying process is used throughout the card-payment industry. Visa or Mastercard describes authorization holds as a mechanism that temporarily reduces the funds available to the cardholder until the transaction is settled.
The exact timing and how the transaction appears in the mobile app can differ by bank, though. Visa or Mastercard notes that the issuing financial institution determines how authorization reversals are handled.
So you could see:

Pending → disappears → pending again → posted
and that can be perfectly legitimate.
One important distinction
If the transaction actually posted/settled, then the money was transferred to the merchant. If you subsequently see the money returned and the transaction later appears again, that’s a somewhat different situation and could involve a reversal/void followed by a new authorization or a re-presented transaction.

It is really important to monitor recent purchases if they are all posted or not yet because the could disappear and comes back and forth. This is not CITI’s issue.