Duplicate transactions after a bank feed import

The instinct when you see the same transaction twice is to delete one. Resist it for sixty seconds, because the two copies are usually not equivalent, and removing the wrong one breaks something that was working.

Where duplicates actually come from

Three causes, and they need different responses.

1. Manual entry plus an added feed line

You wrote the cheque and recorded it. Days later the bank feed downloaded the same payment, and it was added as a new transaction rather than matched to the one already there.

This is the overwhelming majority of duplicates. Note what it means: one copy is linked to something — a bill, an invoice, a customer payment — and the other is a bare bank line.

2. A CSV import overlapping the feed

The feed already covered through the 20th; the CSV started on the 1st. Everything in the overlap now exists twice.

3. The same account connected twice

Two live connections downloading the same transactions. Until the second connection is removed, cleaning up the duplicates is pointless — they come straight back.

Check for this before doing anything else. It takes a moment and it determines whether the cleanup will hold.

The question to ask before deleting anything

What is each copy attached to?

• The manual entry is frequently linked: it may be the payment that marks an invoice paid, the bill payment that closes a vendor bill, or part of a deposit grouping several payments. Delete it and the invoice reopens, the bill unpays, or the deposit loses a component.
• The added feed line is usually standalone — categorised to an account and nothing more.

So the safer removal is normally the feed copy. Normally, not always — if someone has since attached the feed copy to something, that flips.

And the second question, which matters more:

Is either copy marked reconciled?

If a duplicate was included in a completed reconciliation, deleting it changes that period's reconciled total and your next beginning balance stops matching. You will have traded a visible duplicate for a reconciliation discrepancy, which is harder to diagnose.

Removing them safely

In QuickBooks Online, work through the review flow rather than the register:

1. Open the bank transactions and select the Categorized (or Reviewed) tab.
2. Tick the duplicates and select Undo. They return to for-review.
3. From the for-review list, Exclude them.
4. In the Excluded tab, delete them permanently if you want them gone.

Undo → exclude → delete. Going straight into the register and deleting is what breaks reconciliations, because the register doesn't warn you about what the transaction was doing.

For the overlapping-CSV case, identify the overlap window by date first, then remove the imported copies within that window only — not everything the import brought in.

For the double-connection case, disconnect the redundant connection first, then clean up.

Preventing the recurrence

The habit is more valuable than the cleanup, because this problem regenerates:

• Match, don't add. If a feed line corresponds to something already recorded, match it. Adding is for transactions that genuinely aren't in the books yet.
• If there's nothing to match to, ask why. Sometimes the answer is that the payment was never recorded — fine, add it. Sometimes it's that the payment is sitting in Undeposited Funds waiting for a deposit that was never created, and adding it is how income gets recorded twice.
• Start CSV imports after the newest transaction you already have. Check the date range you hold before importing.
• Connect each account once.

What duplicates do to your numbers

Depends what got duplicated, and the direction matters:

• Duplicated expenses understate profit — which sounds harmless until you consider that your CPA files on it.
• Duplicated income overstates profit and, if the sales carried tax, overstates your sales tax liability too.
• Either puts the register out of step with the bank, so reconciliations get progressively harder.
• If duplicates were reconciled, the reconciliations themselves are now unreliable, and the beginning-balance problems start.

When this stops being a DIY job

Clear them yourself when there are a handful, they're recent, none is reconciled, and you can see what each is linked to.

Get help when:

• Duplicates are already inside completed reconciliations.
• They span months, so the P&L has been wrong for a while and periods may already be filed.
• The manual copies are linked to invoices, bills or deposits, so removal has knock-on effects across receivables and payables.
• An import went badly wrong — hundreds of duplicates rather than dozens.
• You are unsure which copy is the real one, which usually means the register has been worked on by more than one person without a convention.

That is QuickBooks cleanup work: identifying every duplicate, determining which copy carries the links, removing safely, and re-reconciling the periods that were affected. One-time fixed fee, quoted in writing after a free file review.

If duplicates keep reappearing because nobody owns the feed, that is what monthly bookkeeping is for — the feed gets reviewed and matched every month, and the question "which of these two is real" never has to be asked a year later.