Why invoices get paid late, and what you can fix

In short

UK businesses are owed an estimated £26 billion in late payments at any time, and owners spend 86 hours a year chasing it. Fixing the trigger that fires the invoice, the documents it has to match, the fields it has to carry and how often you read the aged debt list removes weeks of that wait without any change in customer behavior.

UK businesses are owed an estimated £26 billion in late payments at any one time, an average of £17,000 for every affected business, and the owners chasing that money spend 86 hours a year doing it - 133 million staff hours across the economy, according to the government's 2026 response to its late payment consultation. Part of that wait belongs to the customer and part of it belongs to you: under UK law a commercial payment is not late until 30 days after the customer receives the invoice or you deliver the work, whichever happens later, so every day between finishing a job and sending the invoice is a day the clock has not started.

Late payments are estimated to cost the UK economy almost £11 billion a year, and the government puts the closures caused by them at 14,000 businesses annually, or 38 a day. Four things shorten the part of that wait a supplier controls: when the invoice fires, what it has to match, what has to be on it, and how often you read what is owed.

When a payment is actually late

If you agree a payment date with a business customer, it must usually fall within 30 days for public authorities or 60 days for business transactions. You can agree a longer period than 60 days between businesses, but it has to be fair to both. If you agree no date at all, the law makes the payment late 30 days after the customer receives the invoice or 30 days after you deliver the goods or provide the service, whichever is later. That second limb is the one most suppliers forget, and it is why the terms you agree are worth writing into the contract rather than assuming.

Once a payment is late, the Late Payment of Commercial Debts (Interest) Act 1998 entitles you to claim statutory interest and fixed debt recovery costs. Most small suppliers never claim either, because asking a customer you want to keep for interest is an awkward conversation. That imbalance is what the current reforms are aimed at.

The three documents your invoice has to match

Most business buyers do not pay an invoice because it arrived. They pay it because it matched. At its simplest the invoice has to agree with a purchase order. At its most thorough, and this is standard wherever physical goods change hands, it also has to agree with a delivery note or a goods received note. That three-way match is what releases an approved payment batch on the buyer's side.

None of it is automatic. Somebody in the buyer's warehouse has to confirm receipt, that confirmation has to reach their finance team, and finance has to tie it to the right invoice. If any link is missing the invoice queues, not because anything is wrong with it but because the condition for approving it has not been met. The larger the customer, the more formal the process.

Four things break the chain, and all four are things the supplier controls:

• No signature at the point of delivery. Goods are left at a reception desk or a loading bay, the driver does not wait, and there is no record of who accepted them or when.
• Paper that travels back slowly. A slip signed on Monday reaches the office on Thursday, by which time the invoice has been sitting in the buyer's queue with no matching goods receipt against it.
• No reference to the customer's own order. A note listing products but no purchase order number makes the buyer's accounts team work out which invoice it belongs to, and that identification step is where days go.
• No link between the note and the invoice. A signed note in a filing cabinet and an invoice in an accounting system are two separate records. A request for proof of delivery against invoice 1042 becomes a manual search, and payment waits for the search.

A delivery note that carries the line items, the quantities actually delivered, a signature, a date and the customer's order reference answers all four at once. Generating it from the job rather than typing it separately is what keeps it agreeing with the invoice, which is the point of delivery notes that stay tied to the order.

Decide what fires the invoice

The single largest self-inflicted delay is having no rule about when an invoice is raised. Work finishes on a Friday, invoicing happens whenever the next quiet afternoon arrives, and nobody experiences that as a decision. The Small Business Commissioner is direct about it.

Send your invoice immediately after completing the work, per your agreement, to maintain cash flow. It's tempting to wait until the end of the month and do all your invoices at once, but that could leave you short of cash while waiting for several payments to come in.

- Office of the Small Business Commissioner, Getting invoices right

The arithmetic of monthly batching is worth doing once. A job completed on the second of the month, invoiced at the month end, on 30-day terms, is 58 days from finished work to due date before anybody has done anything wrong. Nobody paid late, nobody disputed anything, and the money is two months behind the work.

A close-out step fixes it, and it does not need to be elaborate. Closing a job means four things: the invoice has been raised and sent, any variations or extra charges are on it, the supporting documents are filed against the job record, and the job is marked complete. The value is in closing being a deliberate action with an owner rather than a state a job drifts into while the field team assumes the office has it and the office assumes the paperwork is coming. Connecting job status to invoice generation removes the handoff where that assumption lives, and the invoice itself then carries what the job record already holds.

Two habits break the rule once it exists. One is letting a single missing item - a signed note, a photo, a confirmation of something agreed on site - hold the whole invoice. The other is treating a snag as a reason to delay: the snag is fixed in a day and the invoice waits a fortnight. Raise it and manage the snag separately.

Check the job record before you build the invoice

The invoice can only bill what somebody wrote down. Four kinds of work routinely never get written down: return visits the engineer assumes are covered by the original scope, small additions agreed verbally on site because saying yes is good service, support calls across a long install, and site time that ran over because access was worse than surveyed.

The direct loss is the obvious one. The secondary loss is worse, because it repeats: when extra time and materials never reach the record, job costing shows the job as more profitable than it was, and that distorted number is what prices the next quote. Scope creep is the visible end of it, but the same mechanism swallows anything done outside the original record.

Get the invoice right the first time

An invoice that has to be corrected and resent is a new invoice as far as the clock is concerned, because the statutory period runs from receipt of a valid invoice. The customer is not at fault and usually will not chase you to fix it - they will simply wait. The Small Business Commissioner's list of what makes an invoice payable is short:

• Invoice date
• Invoice number
• Purchase order number, if you have been given one
• The work completed that the invoice relates to
• Total fee, with VAT detail where it applies
• Payment due date
• Payment terms, as agreed in the contract
• Bank account details

Two additions from the same guidance are worth building into the process. Ask for the purchase order number early rather than at invoice stage, because chasing it afterwards delays submission and delays payment in turn. And describe the work clearly, breaking a large piece into the sub-tasks it was delivered in, so the person approving it can recognize what they are approving.

Look at what is owed every week

Knowing what is outstanding, for how long and at what value is not a month-end task. An aged debt view read weekly surfaces a problem at the seven-day mark, when the options are wider and the relationship is intact, rather than at 30 days when both have narrowed. Debtor days turns the same information into one number you can watch move, and a statement of account sent to a customer with several open invoices often clears two of them without a single chasing email.

The Commissioner's advice on the chase itself is to call the week before payment is due, to confirm the person paying you has everything they need. That call is not a chaser. It is the last chance to catch a missing purchase order number or an unmatched delivery note while there is still time to fix it, and it belongs in the same credit control routine as the aged debt review.

If a payment stays unresolved with a larger client, two free routes exist that most suppliers never use: statutory interest and fixed recovery costs under the 1998 Act, and the Office of the Small Business Commissioner, which takes enquiries about unresolved disputes with larger clients and responds within five business days. Neither one works on an invoice that was never sent.

Sources

• Late payment consultation: time to pay up - government responsePrimary sourceDepartment for Business and Trade · accessed 2026-09-10
• Largest crackdown on late payments in over 25 years as landmark Bill enters ParliamentPrimary sourceGOV.UK · accessed 2026-09-10
• Late commercial payments: charging interest and debt recoveryPrimary sourceGOV.UK · accessed 2026-09-10
• Getting invoices rightPrimary sourceOffice of the Small Business Commissioner · accessed 2026-09-10
• Late Payment of Commercial Debts (Interest) Act 1998Primary sourcelegislation.gov.uk · accessed 2026-09-10
• Nearly three-quarters of small businesses faced late payments in Q1 2025: what can be done?Secondary sourceFinancial Accountant · accessed 2026-09-10

Related pages