• Enquiry
• Quote
• Agree
• Work
• Invoice
• Paid

Administrative Errors

This is the part of the problem you caused, and it is worth separating from the part you did not, because only one of them is within your control.

For a software-side reference alongside this discussion of invoicing, records, and payment administration, Monitask provides guidance on employee PC activity tracking.

Industry compilations attribute a substantial proportion of late payment to incorrect invoices and administrative errors. (Figures vary by source and none is independently audited — treat the proportion as indicative and the direction as sound.)

The seven errors

One. Wrong entity. An invoice addressed to a person when the agreement was with a company, or the reverse. Cost: the time to notice, plus a reissue, plus a restarted clock.

Two. Missing purchase order. The invoice does not enter the system at all. Cost: however long it takes you to chase, plus the full cycle from the point of correction.

Three. Wrong amount. Usually a variation included that was never confirmed, or a deposit not deducted. Cost: a query, and credibility on every other line.

Four. Wrong tax treatment. Rate, registration number, or the net and gross split. Guaranteed rejection in any organisation with a finance function.

Five. Sent to the wrong person. The instructing contact rather than accounts payable. Cost: silence, until somebody forwards it or you ask.

Six. No due date, or a due date expressed as a period. Ambiguity about when the clock started, which is a free extension for anybody who wants one.

Seven. Description that does not match the quote. Same work, different words, and somebody has to reconcile them before paying.

What they have in common

Every one is discoverable before sending.

None requires judgement, negotiation or knowledge of the customer. They are checks, and a list of seven takes two minutes.

Which is why this is the cheapest available improvement and also the one most consistently skipped — because the invoice is written at the end of a job, frequently in the evening, and it feels like the last small task rather than the document that determines when you are paid.

The cost in days

A query discovered by the customer takes as long as their process takes to notice it, plus as long as it takes them to tell you, plus your correction, plus the full payment cycle from that point.

On a thirty-day cycle that is routinely six to eight weeks for a mistake that took thirty seconds to make.

And the customer is not being difficult. A finance function that pays incorrect invoices is a finance function with a problem, and the rejection is them doing their job.

The pattern worth noticing

If the same error recurs, it is not carelessness — it is a process gap.

Wrong entity twice means you are not capturing it at quoting stage. Fix it there rather than resolving to be more careful.

Missing purchase orders repeatedly means you are not asking for one at the start.

Resolutions do not survive a busy month. A step in the process does, and the difference between those two is most of what separates firms that get paid promptly from firms that do not.

The template that removes most of them

One invoice template, filled from the quote rather than written fresh.

If the quote holds the entity, the reference, the terms and the itemised scope, then the invoice is that document with a date and a total, and six of the seven errors cannot occur.

Most accounting software does this, and doing it by copying a previous invoice is the version that propagates the previous invoice's mistakes. Software cannot decide anything for you and it can stop you retyping.

The errors that are not yours

Worth separating, because the response differs.

A customer whose system requires something they never mentioned — a portal, a specific reference format, a supplier onboarding process. Not your error, and the remedy is the same: find out at the start rather than at the invoice.

A customer who changed the entity mid-job without telling you. Their error, your problem, and the fix is a reissue you should not have to make.

And a customer who invents a defect at the point of payment. That is a dispute rather than an error, and it belongs in a different section.

The distinction matters because chasing an error is a correction and chasing a dispute is a negotiation, and treating one as the other wastes time in both directions.

Keeping the record of what happened

Where an invoice is corrected, keep both versions and the message that explains the change.

Two years later, an accounts department reconciling a discrepancy will find one invoice and one credit note and no explanation, and the query that produces lands on you.

A single line in the file — "invoice 218 reissued as 218a, wrong entity, corrected 4 April" — answers it in advance. Records have to survive that long.

What to do when you find one after sending

Immediately, in writing, with a corrected document.

Not a note asking them to amend it themselves. Issue the correction, say plainly what changed, and reference both documents.

And do not treat the original date as still running. It is not, and asserting that it is starts an argument you will lose about a mistake that was yours.

The one worth checking twice

The entity and the amount.

Everything else on the list causes a delay. Those two can cost the debt entirely — an invoice to a dissolved company is a claim against nothing, and an amount that exceeds the agreed figure gives a customer a reason to dispute the whole rather than the difference.

Ten seconds each, at the point of sending.

The short version

• A substantial proportion of late payment is attributed to supplier paperwork errors rather than to unwillingness to pay
• Seven errors: wrong entity, missing purchase order, wrong amount, wrong tax, wrong recipient, no defined due date, and a description that does not match the quote
• Every one is discoverable before sending and none requires judgement — a two-minute check covers all seven
• On a thirty-day cycle, an error found by the customer routinely costs six to eight weeks
• A recurring error is a process gap rather than carelessness, and resolutions do not survive a busy month
• Fill the invoice from the quote rather than from a previous invoice, which propagates the previous invoice's mistakes

For broader background on invoicing, records, and payment administration, see Bloomberg.