Order-to-Cash insight for SMEs
Customer Portals and the Delays in Payment
Supplier portals can strengthen governance, but when onboarding requirements are revealed only after the work is complete, the buyer's process becomes the supplier's cash-flow problem.
What is a supplier portal?
A supplier portal—also called a vendor portal or supplier-onboarding portal—is a secure online system through which a buyer collects supplier information and manages activities such as compliance checks, purchase orders, invoices and payment status. Used well, it gives both parties a consistent record. Used late or without clear ownership, it can add another queue between completed work and collected cash.
Why should an SME have to complete a customer or supplier portal before it can be paid? Sometimes there are sound reasons. A large organisation may need verified bank details, tax information, insurance certificates, cybersecurity declarations and an auditable approval trail. A well-designed supplier portal can make those checks consistent and reduce errors.
The problem is not necessarily the portal. It is the timing, proportionality and lack of transparency. If portal registration is a condition of payment, the buyer should say so before the supplier commits time, incurs costs or starts work. Introducing a lengthy vendor-onboarding process after delivery creates avoidable friction in the order-to-cash process and can make agreed payment terms feel meaningless.
A familiar SME payment-delay story
An SME was invited to survey a site for a major global bank. Its team returned three more times to satisfy different stakeholders, revised the artwork several times and then accommodated the bank's operational constraints. A project expected to require one day of delivery ultimately consumed two and a half days—before counting the extra surveys and administration.
After completion, the SME issued an invoice on five-day terms. Only then did it receive an invitation to join the bank's supplier portal. More than an hour was spent entering credentials, followed by requests for tax and tax-residence certification. Further calls to government departments and a wait for documentation followed. The managing director eventually escalated the issue to the bank, focusing on the undisclosed requirements and their effect on payment.
The commercial lesson: the true cost was not only the late cash. It included unpriced site attendance, revisions, senior-management intervention and hours of non-billable administration.
Five ways to prevent supplier portals delaying payment
Disclose every onboarding requirement before appointment
The buyer should provide one complete checklist with the request for quotation: portal link, required fields, acceptable documents, approval stages, expected lead times and support contacts. The supplier can then price the administration, identify missing evidence and make an informed decision. If registration is mandatory, complete and approve it before the first survey—not after the final invoice.
Agree scope, purchase order and change control
Document who can authorise site visits, artwork changes and additional delivery time. State what the quotation includes, the charge for further attendance and how buyer-caused delays will be treated. A purchase order should match the legal entity, agreed value and invoicing instructions. Each approved change should update the order before the work proceeds.
Give the supplier one accountable owner
A named buyer-side contact should own onboarding from invitation to payment readiness, with a clear service level and escalation route. Procurement, the project sponsor, accounts payable and tax teams may all contribute, but the SME should not have to discover the organisation chart while its invoice ages. The owner should confirm in writing when the vendor record is active and ready to accept an invoice.
Ask only for proportionate evidence—and accept digital alternatives
Buyers should explain why each document is needed, avoid duplicating information already held and accept an appropriate equivalent where possible. The ICO's data-minimisation guidance says personal data should be adequate, relevant and limited to what is necessary. If a certificate of residence is genuinely required, flag it early: the relevant tax authority may have a separate application and validation process, so it should never arrive as a surprise after delivery.
Protect the agreed payment clock
Confirm the invoice submission method, mandatory references, acceptance criteria, due date and dispute process in the contract. A buyer's internal workflow should not silently reset the clock. Current UK payment-practices reporting guidance is especially instructive: for reporting purposes, receipt is when the business receives the invoice—not when its staff eventually enter it into internal software. Pay any undisputed amount on time and resolve genuine exceptions separately.
A practical pre-work portal check
| Question | Evidence to obtain |
|---|---|
| Are we approved to supply? | Vendor number and written onboarding confirmation |
| Who can approve changes? | Named authoriser and documented change-control route |
| What makes an invoice valid? | PO, entity, address, portal and supporting-document requirements |
| When does the payment term start? | Contract wording, invoice receipt confirmation and due date |
| What happens if something stalls? | Named owner, response time and escalation contact |
Fair controls should not externalise cost
Large customers are entitled to operate robust supplier controls. SMEs are equally entitled to understand those controls before accepting the work. Transparency lets both sides plan properly: the buyer protects compliance; the supplier protects margin and working capital.
The scale of the issue is material. Research published by the Office of the Small Business Commissioner in 2025 estimated that late payments cost the UK economy almost £11 billion a year. It also found that affected businesses spent an average of 86 hours a year chasing payment. Better portal design and earlier onboarding will not solve every late-payment problem, but they can remove delays that are entirely self-created.
SMEs should also check a prospective large customer's published payment performance before agreeing terms. The UK reporting service provides useful evidence on average payment times and the proportion paid outside agreed terms. Where payment is late, statutory interest and recovery costs may be available, subject to the contract and circumstances.
Note: This article provides operational guidance, not legal or tax advice. Contractual rights and documentation requirements depend on the parties, transaction and jurisdiction.
Customer portal and payment FAQs
Why do large customers use supplier portals?
They use them to standardise supplier records, verify payment and compliance information, manage purchase orders and create an audit trail. These are legitimate controls, provided the requirements are proportionate, transparent and introduced at the right time.
When should supplier onboarding be completed?
Ideally before the supplier attends site, incurs cost or begins delivery. At a minimum, the buyer and supplier should agree the portal requirements, responsible contact, invoice route and payment start date before appointment.
Does uploading an invoice later change the agreed payment terms?
Not automatically. The answer depends on the contract and circumstances. Suppliers should retain evidence of when the invoice was first delivered and seek professional advice where necessary. For statutory UK payment-practices reporting, GOV.UK guidance says receipt is not deferred merely until an invoice enters the buyer's software.
Six useful sources to check
- Office of the Small Business Commissioner: Late Payments Research
- GOV.UK: payment-practices reporting guidance
- Office of the Small Business Commissioner: Fair Payment Code
- GOV.UK: late commercial payment, interest and recovery
- Information Commissioner's Office: data minimisation
- HMRC: certificate of residence or letter of confirmation
Where is your order-to-cash process losing time?
Blueringed's O2C Health Check helps identify hidden hand-offs, onboarding delays and control gaps that slow invoicing and payment.
Explore the Blueringed O2C Health Check