Policy: Accuracy of invoices to ThinJack Ltd

Updated: 20th August 2026.

If you deliver goods or services to ThinJack Ltd, we will pay you in accordance with our purchase order and agreed payment terms. We value our suppliers and the service they provide.

However, we receive, increasingly, “surprise” invoices which turn out to be incorrect. These are often from well established B2B organisations which we have never dealt with before, or did not know had any reason to invoice us.

In the past eight months, two cases took a significant amount of our time. One was a water company pursuing us for historical drainage charges relating to premises about 500 metres from ours, with a similar but different address. The other was an express carrier which invoiced us for UK import duty, despite a duty free quota which meant that no duty was due. In both cases, we had to work out what had gone wrong, research the issue and explain it back to the invoicing organisation. Both cases involved debt collectors and threats of litigation if we didn't pay the erroneous invoice.

The first was resolved in our favour, including payment of our costs. The second took nearly four months before the carrier identified its error and credited the invoice.

Together, these cases took approximately 160 hours of our time: 9% of one person's working year. This time should have been spent supporting our customers and building our business.

Our established charge out rate for this type of work is GBP 180 per hour plus UK VAT, in addition to any external costs we incur. We reserve the right to seek recovery of these costs where we have had to deal with an invoicing error.

What this means to you:

If ThinJack Ltd reject an invoice and explain why we believe it is incorrect, please pause before escalating it. We may see something that you cannot see from within your organisation. Please investigate it properly and speak to others in your organisation. Try to understand the situation from our viewpoint.

We are happy to discuss a disputed invoice by 'phone with a single, knowledgeable contact person. We then expect the matter is closed out by you: promptly, efficiently and proactively. If you remain convinced that your invoice is correct, we will say why we disagree. If we know that our position is correct, we will persist in persuading you to change yours.

Please do not turn an incorrect or disputed invoice into debt collection or litigation without first understanding why we have rejected it. This creates unnecessary costs for everyone. This policy applies regardless, even if ThinJack Ltd has previously had a trading relationship with the entity sending the invoice.

Before sending an invoice or payment demand to ThinJack Ltd, please check that it is “real world valid”, with our purchase order number.The underlying transaction or liability must actually relate to ThinJack Ltd and it is addressed to our registered office.

Checking before sending an invoice saves everyone a great deal of time, energy and money afterwards. Thank you to all those organisations who already take this approach. We value the relationships we have with you.

We may refer you to this policy if we dispute an invoice.