Katherine has over 25 years experience in delivering high volume, value, innovative or complex procurements for the public sector – from PFIs, to commercial joint ventures, frameworks, and strategic partnerships. 

Katherine also supports suppliers and contractors working with and bidding to the public sector, providing strategic bidding guidance to ensure successful and sustainable growth. Her practice covers non-contentious and contentious matters and she has advised on many well known procurement cases. 

Katherine and her team are well known across numerous sectors including health, education, housing and regeneration, technology, and outsourcing. Katherine is a nationally ranked specialist in her area by Chambers & Partners and a published expert for Practical Law and Lexis Nexis PSL, amongst other publications. 

Katherine’s relevant experience includes:  

• Advising DWP on its three-phase telephony and call-centre procurements 

• Advising the Cabinet Office on the procurement for a pension's administrator for the entire Civil Service Pension Scheme and the Royal Mail Pension Scheme 

• Advising DSIT and eight other government departments on the "Matrix Programme" - a large IT procurement for systems integrator and SaaS services 

• Advising FCDO Services Limited on a number of procurement and research contracts 

• Being the go-to procurement adviser to National Highways under our appointment to provide all procurement and construction advice on major projects 

• Advisor to the DFE on school decarbonisation scheme and other capital projects 

• Advising LocatED (wholly owned subsidiary of DfE) on a £100m FM procurement 

• Adviser to number of NHS Trusts and Foundation Trusts on high value procurements including EPRs and managed pathology services 

• Advising a leading private sector outsourced service provider on its UK business 

• Advising a number of private health suppliers on their tenders into the NHS and potential challenges 

Endoresements:

• “I think Katherine Calder is fantastic. I can’t rate her highly enough. She is through, responsive and pragmatic.” - Chambers and Partners UK 2026, Public Procurement respondent 

• “Katherine Calder is a legal gem.”  -Chambers and Partners UK 2026, Public Procurement respondent 

• “Excellent, responsive and a pleasure to work with” - Chambers and Partners UK 2025, Public Procurement respondent