VOX NOVA Fixed Voice OFFICIAL (FVO) & Enterprise Voice (EV)

Defence Digital

Published: Jul 20, 2026

Updated: Jul 20, 2026

Source: uk_fts

About This Opportunity

This is a services contract in the information and communication technology sector, with a focus on Software, Network Infrastructure, Cloud Services and Internet. Located in United Kingdom, Europe, this opportunity is open to firms and consortiums, with an estimated budget of GBP 55.0 million.

Published through UK FTS - Find a Tender Service, a national government procurement portal. Public procurement tenders follow the country's national bidding regulations and may have specific eligibility and documentation requirements for services in the information and communication technology sector. Service contracts are typically evaluated on both technical quality and price, and may require bidders to demonstrate relevant experience and qualified personnel. This is an advance notice — the formal tender is expected to be published shortly. Interested parties can use this time to prepare documentation and identify potential partners.

Description

1. Purpose
The Authority Enterprise OFFICIAL voice system is ageing and requires modernisation. The future end state is a hybrid solution that fuses on-premises calling capability with the flexibility of a cloud-native call management service.

This procurement is for the design, build, migration, and operation of the end state architecture whilst ensuring the users maintain capability throughout the process.
This encompasses design and delivery of a cloud native call management core (Software as a Solution (SaaS) or UK zoned public cloud), migration of existing gateways and SIP native Private Automatic Branch Exchange (PABX), modernisation and Session Initiation Protocol (SIP) enablement or replacement of legacy, non SIP PABX, through life support for legacy PABX estate until migration, resilient public telephony breakout and partner connectivity, local survivability for specific sites, a field engineering competence to ensure compliance with Authority processes and service management.
The existing PABX estate is mostly analogue lines with a small amount of digital and Voice Over Internet Protocol (VoIP) ; it is not envisaged that this will change due to the cost and complexity of replacing the existing cabling.
2. Background
The Ministry of Defence’s (MOD’S) Integrated User Services (IUS) VOX NOVA (VN) Programme is responsible for the delivery of fixed voice telephony at OFFICIAL.
The current FVO service supports Defence outputs, including safety-related and operational use cases. User access is provided through a mixed estate of analogue lines, digital extensions and a smaller number of Voice over IP endpoints, with services terminating on site-based Private Automatic Branch Exchange (PABX) where required.
The existing estate includes a mixture of refreshed IP-native OpenScape PABX, HiPath 3x00 switches and legacy Integrated Services Digital Exchange (iSDX) and Meridian switches. Site-based PABX trunks and Voice Over Internet Protocol (VoIP) handsets currently terminate on a geo-resilient call management core, with connectivity using Session Initiation Protocol (SIP) and Internet Protocol (IP)-encapsulated H.248 for legacy PABX.
Permanent overseas locations use OpenScape PABX with local public telephony breakout where required to support local survivability.
The current FVO core is based on in-service Ribbon C20 soft-switch infrastructure hosted in contractor facilities. It provides Time Division Multiplexor (TDM) and SIP trunk functionality, analogue terminal adapter support, H.248 media gateway support, public telephony breakout and secure boundary protection/partner connectivity
3. Outcomes the Authority is seeking
The Authority is seeking a resilient, supportable and Value-for-Money (VfM) service that maintains continuity while progressively removing reliance on the existing core and obsolete PABX estate.
a. Maintain continuity of critical fixed-voice services throughout mobilisation, build and migration.
b. Deliver a modern call-management capability using a secure cloud-native or Software as a Solution (SaaS)-based model, with on-premises survivability where required.
c. Migrate existing gateways, SIP-capable PABX and endpoints using controlled pilots and migration waves.
d. Modernise, SIP-enable as a priority and replace legacy PABX sites, including Meridian, Realtis, HiPath and iSDX, and other agreed non-SIP sites under the future-service delivery scope. Facilitate the withdrawal from the incumbent Data Centres by enabling legacy PABX to communicate to a SIP-based cloud calling platform. Replacement completed subsequently.
e. Provide specialist support to the legacy PABX estate, including Meridian, Realtis, HiPath and iSDX systems, for as long as each platform remains in service and pending modernisation and migration.
f. Provide resilient public telephony, partner connectivity, numbering, dial-plan, emergency-calling and local-survivability services.
g. Establish service management, monitoring, field engineering, security assurance, testing, early-life support (ELS) and through-life operations.
h. Provide a transparent commercial model covering implementation, migration, recurring services, consumption, spares, field engineering, change and exit.
The above describes the Authority's current outcome hypothesis rather than a prescribed solution. Suppliers are invited to identify alternative delivery patterns that better meet the outcomes, reduce risk or improve value.
4. Proposed procurement approach
Using the Competitive Flexible Procedure under the UK Procurement Act 2023 (PA23), the Authority will engage directly with all participating suppliers via direct dialogue and negotiation to further develop and optimise their bids.
Lot A Vox Nova
Design, build, integrate, migrate, operate and support the future VN service, including core platform, gateways, SIP estate and modernisation/migration of agreed legacy PABX and other non-SIP sites.
Includes SIP enablement, replacement, modernisation, migr

Data provenance

This notice is sourced from UK FTS - Find a Tender Service and was originally published on July 20, 2026. Last refreshed today. Reference: 068356-2026. BidsFactory mirrors official procurement notices and links back to the source for full legal text.

Frequently asked questions about this tender

Where will the contract be performed?

The contract is for delivery in United Kingdom. Foreign bidders should review local registration, taxation, and any in-country presence requirements before submitting.

How can I submit a bid?

Visit UK FTS - Find a Tender Service to access the full notice, required documents, and submission instructions. Quote reference 068356-2026 when communicating with the contracting authority.

Who is the contracting authority?

This notice was issued by Defence Digital in United Kingdom. The authority is responsible for evaluating bids, awarding the contract, and managing performance.

What type of contract is this?

This is a Services contract in the Information & Communication Technology sector. The classification helps bidders match the opportunity to their qualifications and registered scope of supply.

What is the estimated budget?

The estimated contract value is £55,000,000 - £55,000,000. Bidders should ensure their proposals are consistent with this range and account for any local taxes and contract execution costs.