UK stats body snoozes legacy tech overhaul as Treasury tightens purse strings

ONS acknowledges it might be a costly decision in the long run

The UK's Office for National Statistics (ONS) is slowing migration away from legacy systems in response to budget limitations set by HM Treasury.

In its Strategic business plan: April 2025 to March 2026, the ONS – the independent arm's-length body responsible for creating official statistics – warned it would have to put the brakes on a few of its programs because of straitened public spending.

"We have also chosen to protect budgets (in nominal terms) for our range of economic statistics and essential security to protect the data we hold. Finding significant additional funding for survey operations within a 'flat cash' settlement for 2025/26, while absorbing the costs of inflation and civil service pay awards, has required tough choices," it said.

Included in a number of programs on the back burner is the transition away from legacy IT systems, which it acknowledged would have a financial downside in the long term.

"We will limit the pace of our transition away from legacy systems and our ability to move to more agile and productive alternatives, reducing our ability to mitigate our strategic risk in this space, and increasing uncertainty related to future costs," the missive said.

Information from May 2021 suggests the ONS counts the Ingres database and the Lotus Notes information platform among its legacy systems, both of which date back to the last century.

"We have made significant progress towards our objective of replacing 80 percent of our legacy services. The migration of legacy services into the VMware-managed service in AWS is underway and will be a key deliverable in exploiting additional services that AWS cloud offers," the update said [PDF].

Contract information suggests [Excel] the ONS had the right to use Lotus Notes software from HCL until March 31, 2024. The Register has asked the ONS to comment.

The UK's statistics provider has also said it would "remove data science support to the rest of government" as a result of budget restraints.

The move comes as the government aims to make data and digital technologies a central plank of its plans to improve efficiency in the public sector. But a former Number 10 advisor warned last week that a lot of people in government who have senior digital or data roles are not "technologists or data people." ®