Duplicates rarely look like duplicates. The file names differ, one copy is a phone photo and the other a PDF, and the second arrives three weeks later attached to a reminder. Caught at month end, a duplicate costs an hour of untangling. Missed, it costs a double payment that someone has to chase back.
How the same invoice gets in twice
- Two channels. The supplier emails the invoice and also posts it, or a director forwards a photo from their phone.
- Reminders. A "friendly reminder" arrives with the original invoice attached, and it looks like new work.
- Two people. One bookkeeper registers it from the inbox while another enters the paper copy.
- Already in the ledger. The invoice was entered by hand or by another tool, and now it's uploaded again.
- Small differences. "INV-0042" on one copy and "0042" on the other, or a reissued invoice with a new date but the same amount.
What it costs
The direct cost is a payment made twice. Some suppliers notice and refund, and many credit it against the next invoice. Either way, someone spends time finding it, emailing the supplier and correcting the ledger.
The indirect costs add up too:
- Wrong VAT. Input VAT is claimed twice until the duplicate is reversed.
- Wrong payables. The aged payables report shows money owed that isn't, so cash planning is off.
- Month-end work. Duplicates usually surface during the bank reconciliation, when a payment doesn't match, which is the worst time to find them.
Four checks that catch most duplicates
- One way in. Send every supplier invoice to one mailbox per company. Fewer channels mean fewer copies. See how to organise supplier invoices.
- Check supplier and invoice number before booking. A match on both is almost always a duplicate.
- Then check supplier, amount and date. The same amount on the same day from the same supplier under a different number needs a closer look: it may be a reissue.
- Check against the ledger, not just the inbox. An invoice already booked by another route won't be in today's pile.
What automation adds
Doing those checks by hand on every invoice is exactly the kind of work that gets skipped when the month is busy. Software can do them on every document as it arrives.
Invoreg compares each new document with what's already in the workspace and with bills already in the accounting software. A match is flagged as a duplicate and linked to the original, so it isn't registered twice by accident. Documents already booked in the accounting software are matched to their uploads and marked registered, so "already booked, now uploaded" is caught too. The duplicates view lists every flagged copy in one place. See duplicates, filters and search.
If you want to see how often it happens in your own books, try it on your own invoices. The first 20 are free.