Diploma lifts FY26 guidance again after 15% organic growth in strong third quarter

Diploma's Q3 update at a glance

Diploma has delivered a strong third quarter, prompting the FTSE 100 value-add solutions group to raise its full-year guidance again.

Organic growth reached 15% for the nine months ended 30 June 2026. Organic growth measures performance excluding the effect of acquisitions and currency movements, making it a useful indicator of how the existing businesses are trading.

Management said momentum from the first half continued into Q3, supported by excellent execution and favourable market conditions in Controls. Diploma now expects FY26 organic revenue growth of 14%, up from its previous forecast of 12%.

The operating margin forecast has also increased materially, from around 25% to approximately 26.5%. Combined with acquisition growth, this is expected to produce operating profit growth of around 42% at constant currency.

Constant currency strips out exchange-rate movements, allowing investors to assess the underlying performance of the business more clearly.

Key figures

Metric	Latest FY26 guidance	Previous guidance or comparison
Nine-month organic growth	15%	Not disclosed
FY26 organic revenue growth	14%	12%
Acquisition contribution to reported growth	6%	Unchanged
FY26 operating margin	c.26.5%	c.25%
FY26 operating profit growth	c.42%	Further c.7% upgrade to consensus
Analyst consensus adjusted operating profit	£454 million	As at 15 July 2026

The guidance is presented at constant currency. Diploma did not disclose nine-month revenue, operating profit or cash flow figures in this update.

Controls remains the standout performer

The strongest commentary concerned Diploma's Controls businesses, where management highlighted both favourable markets and excellent execution.

IS Group, Clarendon, Peerless and Windy City Wire all continued to produce double-digit growth. The update does not provide individual growth rates or revenue figures for these businesses, but the breadth of the performance is encouraging.

Strong trading across several operations suggests the result is not dependent on one isolated success. It also indicates that Diploma is capturing demand effectively where end markets are supportive.

However, favourable market conditions are part of the picture. Investors will want to see how much of the current growth can be sustained if those conditions become less helpful.

Seals improves while Life Sciences stays resilient

Performance in Seals was described as a little stronger than in the first half. That is positive, although Diploma did not quantify the improvement or disclose a growth rate for the division.

Life Sciences faced more difficult markets. Management described its performance as resilient, suggesting that the business held up reasonably well despite the challenging backdrop.

This is a mixed but credible divisional picture. Controls is driving strong momentum, Seals has improved and Life Sciences is weathering weaker conditions. The update does not suggest that every part of the group is enjoying the same level of demand.

For investors, the key question is whether continued strength in Controls and improvement in Seals can outweigh the pressure in Life Sciences. The upgraded group guidance indicates that this has been the case so far.

CDM adds a US interconnect platform

Diploma completed its acquisition of CDM on 25 June 2026. The deal establishes what the company describes as a strong US interconnect platform, with attractive positions principally in defence.

Interconnect products help transmit power or signals between components and systems. Diploma did not disclose CDM's purchase price, revenue, profit contribution or expected financial returns in this announcement.

Acquisitions announced to date are expected to add 6% to reported FY26 growth, unchanged from the previous guidance. That sits alongside the newly raised organic growth forecast, giving Diploma two sources of expansion.

The company also reported a strong acquisition pipeline and significant balance sheet headroom. No numerical details were provided for either, so investors cannot assess the likely pace or size of future deals from this update alone.

Why the margin upgrade matters

The increase in expected operating margin from around 25% to approximately 26.5% is one of the most important parts of the announcement.

Revenue growth is valuable, but stronger margins indicate that more operating profit is being generated from each pound of sales. The combination of higher organic revenue guidance and a 1.5 percentage point increase in expected margin supports the forecast for operating profit growth of around 42%.

Diploma said this represents a further upgrade of approximately 7% to consensus. Analyst consensus adjusted operating profit for FY26 stood at £454 million as at 15 July 2026.

The announcement does not give a new operating profit figure in pounds, so it would be inappropriate to treat any calculated estimate as formal company guidance.

What looks positive for Diploma investors?

There is plenty for shareholders to welcome:

• Organic growth of 15% shows strong underlying trading momentum.
• FY26 organic revenue guidance has increased from 12% to 14%.
• Expected operating margin has risen from around 25% to approximately 26.5%.
• Controls is producing double-digit growth across several businesses.
• Seals performed a little better than in the first half.
• CDM provides a new US interconnect platform, principally exposed to defence.
• Diploma says it has a strong acquisition pipeline and significant balance sheet headroom.

Most importantly, the upgrade is not limited to revenue. The higher margin outlook means management expects the improved trading performance to translate into stronger profit growth.

What are the risks and unanswered questions?

The update is strong, but it is brief and leaves several points unresolved.

Life Sciences markets remain challenging, and the scale of pressure within that division was not quantified. Controls is also benefiting from favourable market conditions, which may not persist indefinitely.

Diploma remains an active acquirer. Acquisitions can support growth, but their success depends on disciplined pricing, integration and delivery. The announcement provides no purchase-price or return details for CDM, while the group's balance sheet headroom is described rather than quantified.

Currency is another consideration. Guidance is stated at constant currency, so actual reported results may differ as exchange rates move.

There are also no updated figures for cash generation, net debt or working capital. Those details will be important when assessing the quality of growth and Diploma's capacity for further acquisitions.

The bottom line

Diploma's third-quarter update points to strong execution and broad momentum, led by Controls. Raising organic revenue growth guidance to 14% would have been encouraging on its own, but the operating margin upgrade to around 26.5% makes the announcement more significant.

Expected operating profit growth of approximately 42%, representing a further roughly 7% upgrade to consensus, shows how strongly the higher sales and margins are flowing through the business.

The main areas to watch are the difficult Life Sciences markets, the durability of favourable conditions in Controls and the financial details behind Diploma's acquisition strategy. Investors should receive a fuller picture when the company publishes its full-year results on 17 November 2026.