It doesn't.
The premise that the Ministry of Justice (MoJ) pays the Home Office for having razor wire on prisons is incorrect. The Ministry of Justice is responsible for its own custodial estate and funds its security measures, including the installation of razor wire, through its own budget.
Here is a breakdown of how the funding and responsibilities work:
Ministry of Justice (MoJ) Responsibility: The MoJ has the primary responsibility for the prison system in the UK. This includes all aspects of prison construction, maintenance, and security, which are managed through the His Majesty's Prison and Probation Service (HMPPS).
Funding for Security: The MoJ provides the funding for security measures like razor wire as part of construction and refurbishment projects. These costs are covered by the MoJ's departmental budget, which is allocated during the government's spending reviews.
No Inter-departmental Payment for Wire: There is no system where the MoJ pays the Home Office for the physical supply or use of razor wire on prison perimeters. The Home Office is a separate government department with different responsibilities, primarily related to policing, immigration, and national security.
"Fines" Myth: There is a common "myth" within the prison system that prisons pay fines to other departments or organisations for various issues (e.g., using "illegal" razor wire, regime shutdowns). These "fines" do not exist; any internal penalties are accounted for within the MoJ's own budget and recycled into the next year's spending, not paid to another department like the Home Office.
In summary, the MoJ manages and pays for its own security infrastructure, including razor wire, to prevent escapes and unauthorised access. The Home Office is not involved in funding or providing this specific equipment to the MoJ
I do however have a dislike of both barbed wire and razor wire where animals, livestock and domestic pets etc,are at risk, but criminals,incarcerated on outside, , couldn't care less, in fact,, run 400,000 volt through it too.