Why Even the Biggest Telecom Providers Get Billing Wrong - and How to Spot It Early

In the world of corporate telecoms, billing accuracy should be a given. After all, we’re talking about multi-million-pound contracts managed by some of the UK’s largest providers. Yet, month after month, our analysts see the same story: duplicated charges, outdated tariffs, and services still billed long after being decommissioned.

It’s not about blame. These aren’t isolated cases of negligence - they’re symptoms of scale and complexity. When a single organisation runs thousands of mobile connections, fixed lines, data services and IoT devices across multiple carriers, even the most sophisticated systems can fall out of sync.

Why billing errors happen

Telecom billing errors typically emerge from four root causes:

1. Legacy platforms – Even major providers still rely on a patchwork of old billing engines behind the scenes. Merging data across them is messy and error-prone.

2. Manual provisioning – Services are often added or removed manually, increasing the risk of missed disconnections or duplicated records.

3. Contract misalignment – Tariff updates or discounts agreed in procurement don’t always flow through to billing.

4. Usage lag – Data consumption, roaming, and shared allowances are billed on different cycles, causing temporary or persistent mismatches.

A few pounds difference on one line doesn’t sound like much. But when multiplied across tens of thousands of services every month, those variances can quietly become six-figure overspends.

How to identify hidden telecom overspend

Finance and IT teams can spot early warning signs of telecom billing drift by watching for:

• Invoices that grow steadily without obvious cause.

• Duplicate service IDs or missing cost centres.

• Lines with zero usage still being charged.

• Inconsistent data between invoices and asset registers.

Without automated validation, these issues often go unnoticed for months — even years.

The Temis approach

At Temis, we combine automation with forensic data validation to detect and prevent billing errors across all major UK carriers. Our reconciliation engine matches contract rates, call data, and live inventory to ensure every pound charged has a reason behind it. When it doesn’t, we flag it and feed corrections straight into finance workflows.

It’s the same principle that drives good finance management everywhere: trust, but verify. We just happen to do it across hundreds of thousands of telecom assets.

The takeaway

Telecom billing errors aren’t rare — they’re routine. The key isn’t trying to eliminate them entirely, but building processes that identify and correct them fast.

That’s where Temis comes in: turning complex telecom data into financial clarity.

Temis helps large organisations reconcile telecom costs, manage inventory, and recover overspend through automation and insight.

temis.co.uk