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PROCUREMENT OPPORTUNITY

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

Defence Digital · Preliminary market engagement notice on Find a Tender

Tender information last checkedLast checked 26 Sept 2026, 21:51.

Opportunity overview

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, migration, acceptance and operational support of transitioned sites. Market Consideration - Vox Nova is expected to require broad capability across cloud or SaaS voice platforms, systems integration, security, migration, service management, public telephony, gateways, networking and through-life service delivery. Lot B Legacy PABX support. Provide specialist through-life support for the in-scope legacy PABX estate, including Meridian, Realtis, HiPath and iSDX systems, while each system remains operational and awaiting migration under Lot A. Excludes SIP enablement, modernisation, replacement, and migration. Sites leave Lot B baseline after formal migration and service acceptance into Lot A. Market Consideration - Legacy PABX support is expected to require specialist engineering expertise, access to appropriate spares, and experience in maintaining ageing or obsolete PABX platforms. The MOD is committed to supporting the Government’s SME (Small and Medium sized Enterprises) policy and wants to encourage wider SME participation throughout the supply chain. The MOD’s goal is for at least 25% of the Authority’s total spend to be placed with Small SMEs, either directly or through the supply chain. Lot B may sit with niche or specialist organisations, including SMEs, that do not have the scale or breadth required to deliver Lot A. Separating Lot B is therefore intended to: a. Make the requirement more accessible to specialist suppliers and SMEs. b. Avoid requiring a specialist legacy-support provider to bid for a substantially larger future-service transformation contract. c. Allow the Authority to test whether specialist legacy support can be secured more effectively and economically through a discrete lot. 5. Planning assumptions: UK -150 Overseas - 30 ~113 sites; ~180 nodes; . up to ~65,000 telephone endpoint is any physical or virtual device that originates or receives calls. Anticipated contract term: 5 years. Suppliers should treat volumes and dates as planning assumptions only. Classification: Official

Classification

  • CPV32520000 — Telecommunications cable and equipment
  • CPV32551200 — Telephone exchanges
  • CPV50330000 — Maintenance services of telecommunications equipment
  • CPV50332000 — Telecommunications-infrastructure maintenance services
  • CPV64200000 — Telecommunications services
  • CPV64227000 — Integrated telecommunications services
  • CPV72222300 — Information technology services

Lots

  • Lot 1Value not stated

Documents and notices

Published notice details

Additional information from the published procurement release. Fields appear only when supplied by the source; check the original notice and tender documents before acting.

Scope, procedure and submissions

Id
715870499
Main Procurement Category
services
Above Threshold
Yes
Status
planned

Legal basis

Id
2023/54
Scheme
UKPGA

Special regime

defenceSecurity

Communication

Future Notice Date
21 May 2027, 23:59

Lots and requirements

Entry 1
Id
1
Has Renewal
Yes
Status
planned

Suitability

Sme
Yes

Contract period

Starts
1 Jun 2028, 00:00
Ends
31 May 2033, 23:59
Max Extent Date
31 May 2035, 23:59

Items and delivery

Item 1
Id
1
Related Lot
1

Additional Classifications

Entry 1
Scheme
CPV
Id
50330000
Description
Maintenance services of telecommunications equipment
Entry 2
Scheme
CPV
Id
50332000
Description
Telecommunications-infrastructure maintenance services
Entry 3
Scheme
CPV
Id
64200000
Description
Telecommunications services
Entry 4
Scheme
CPV
Id
72222300
Description
Information technology services
Entry 5
Scheme
CPV
Id
32551200
Description
Telephone exchanges
Entry 6
Scheme
CPV
Id
64227000
Description
Integrated telecommunications services
Entry 7
Scheme
CPV
Id
32520000
Description
Telecommunications cable and equipment

Delivery locations

Entry 1
Region
UK
Country
GB
Country Name
United Kingdom
Entry 2
Region
GI
Country
GI
Country Name
Gibraltar
Entry 3
Region
BN
Country
BN
Country Name
Brunei
Entry 4
Region
NP
Country
NP
Country Name
Nepal
Entry 5
Region
CY
Country
CY
Country Name
Cyprus
Entry 6
Region
BZ
Country
BZ
Country Name
Belize
Entry 7
Region
DE
Country
DE
Country Name
Germany
Entry 8
Region
FK
Country
FK
Country Name
Falkland Islands

Planning and budget

Milestones

Entry 1
Id
engagement
Type
engagement
Description
Pre-Market Engagement process Step One. The Authority invites you to download and complete the RFI Questionnaire "PQQ: 715870499 RFI Questionnaire FVO & EV" via Defence Sourcing Portal (DSP). https://contracts.mod.uk/esop/ogc-host/public/mod/web/login.html?VISITORID=2abdd65f-9458-4c22-bde4-f27d6b530265&_ncp=1784555640378.955037-1 View DSP Opportunities Please follow all instructions stated in the RFI Questionnaire. RFI must be submitted before Wednesday 12th August, Noon The IUS Programme (Authority) advises that no engagement meetings will be held as part of this RFI. Step Two Further engagement activity may be undertaken in January to March 2027, and suppliers will be informed via the Defence Sourcing Portal (DSP) if such activity is initiated, under this Notice. If any changes occur to the above, all future communications will be made via Defence Sourcing Portal (DSP) to all suppliers who have expressed an interest in this notice Non‑participation in any future engagement will not influence subsequent procurement decisions and will not preclude any organisation from submitting a tender in any future competition.
Due
31 Jan 2027, 23:59
Status
scheduled

Documents

Entry 1
Id
068356-2026
Document Type
marketEngagementNotice
Notice Type
UK2
Description
Preliminary market engagement notice on Find a Tender
Published
20 Jul 2026, 15:31
Format
text/html

Buyer, suppliers and contacts

Organisation 1
Name
Defence Digital
Id
GB-PPON-PHVX-4316-ZVGZ

Identifier

Scheme
GB-PPON
Id
PHVX-4316-ZVGZ

Address

Street Address
Westwells Road
Locality
Corsham
Postal Code
SN13 9NR
Country
GB
Country Name
United Kingdom
Region
UKK15

Contact

Name
Phil Taylor

Roles

buyer

Details

Classifications

Entry 1
Scheme
UK_CA_TYPE
Id
publicAuthorityCentralGovernment
Description
Public authority - central government

Recorded locations

  • Buyer location · Corsham · UKK15 · SN13 9NR · United Kingdom
  • Delivery location · BN · Brunei
  • Delivery location · BZ · Belize
  • Delivery location · CY · Cyprus
  • Delivery location · DE · Germany
  • Delivery location · FK · Falkland Islands
  • Delivery location · GI · Gibraltar
  • Delivery location · NP · Nepal
  • Delivery location · UK · United Kingdom

Notice and amendment history

2 published notice versions reviewed by ProcuraAxis.

2 VERSIONS
  1. 066158-2026Pipeline notice on Find a Tender ·
  2. 068356-2026Preliminary market engagement notice on Find a Tender ·