Search UK public tenders and contract notices
Official notices, one row per procedure. Filters use published facts only: delivery region from the notice, buyer type from the official classification, route and agreement type as published, never a Tenderline score.
Live opportunities
Showing 551–600 · submission window open: deadline in the future or not published.
- Closes · 16 days leftOpen procedure
Royal Hospital for Children Money and Debt Advice Service
NHS Greater Glasgow and Clyde · NHS & health · Scotland
The service will operate from the RHC and target families whose child is in hospital or who are regularly attending outpatients at the RHC or are unable to access community services due to their child’s diagnosis/condition/caring responsibi…
- Value
- £250k
- Term
- 12 months
- Submit via
- Public Contracts Scotlandlogin required
- Published
- #078e96
- Closes · 37 days leftBelow threshold - open competitionSME suitable
Burnley Canalside Conservation Area Appraisal, Masterplan and Design Guide
Burnley Borough Council · Local authority · North West England
Tenders are invited from contractors having the resources, sufficient capacity and experience working with Local Authority clients to prepare conservation area appraisals, masterplans and design guides. All works must be in accordance with …
- Value
- £75k
- Term
- 4 monthsup to 5 months with extensions
- Submit via
- ProContract (Due North)login required
- Published
- #078e93
- Closes · 19 days leftOpen procedureSME suitable
Contract for the Provision of General Carpentry Maintenance
Police and Crime Commissioner for South Wales · Police & fire · Wales (Cymru)
South Wales Police are seeking a Contractor to provide planned and reactive carpentry services, together with associated works.
- Value
- £6.0m
- Term
- 4 yearsup to 6 years with extensions
- Submit via
- Jaggaerlogin required
- Published
- #078e86
- Closes · 68 days leftOpen procedure
Rutherglen & Cambuslang Housing - Insurance Contract & Services
Rutherglen & Cambuslang Housing Association C/o Howden UK Insurance Brokers Ltd · Housing · Scotland
All Risks Property Insurance Loss of Rent / Alternative Accommodation Insurance Property Owners Liability Insurance & Terrorism Terrorism Terrorism Insurance
- Value
- £372k
- Term
- 3 years
- Submit via
- Public Contracts Scotlandlogin required
- Published
- #078e7e
- Closes · 15 days leftCompetitive flexible procedureSME · VCSE suitable
Cheetham CE Community Academy Tender for Cleaning Services
Cheetham CE Academy · Nationwide (UK)
Cheetham CE Community Academy is a primary school based in Manchester with circa 600 pupils on roll, aged 3 to 11 years. They are seeking a contractor to provide cleaning of a regular and routine nature, together with more specific periodic…
- Value
- £309k
- Term
- 3 yearsup to 5 years with extensions
- Submit via
- MultiQuotelogin required
- Published
- #078e74
- Closes · 11 days leftCompetitive flexible procedureUtilities4 lots
DCC Wastewater Sludge Cake Haulage
Dwr Cymru Cyfyngedig · delivery region not published
Dŵr Cymru Welsh Water (DCWW) is seeking suitably qualified and experienced suppliers to provide wastewater sludge cake haulage services across four Lots: - **Lot 1 – Intercompany Haulage (North Wales)** - **Lot 2 – Intercompany Haulage (Sou…
- Value
- £6.0m
- Term
- 4 yearsup to 8 years with extensions
- Submit via
- Jaggaerlogin required
- Published
- #078e63
- Closes · 3 days leftBelow threshold - open competitionSME suitable
ESPLANADE GARDENS, ROCHESTER LANDSCAPE IMPROVEMENTS - OCT 2026
Medway Council · Local authority · South East England
Revised specification from July/Aug opportunity due to budget limitations. Landscape improvements and associated works including new playground at Esplanade Gardens, Rochester. Single contract with no staged delivery The Contract will be fo…
- Value
- £400k
- Term
- 6 monthsup to 12 months with extensions
- Submit via
- Delta eSourcingpublic page
- Published
- #078e5d
- Closes · 11 days leftOpen procedure2 lotsSME suitable
Assessment Venue and Invigilation Services - UK & EU
General Medical Council (GMC) · Local authority · Nationwide (UK)
Background information The General Medical Council (GMC) is the regulator for doctors, physician associates (PAs) and anaesthesia associates (AAs). There are various routes to GMC registration for those wishing to work in the UK. All candid…
Likely replaces the contract held by The British Council +2
- Value
- £2.5m
- Term
- 3 yearsup to 6 years with extensions
- Submit via
- portal not identified
- Published
- #078e58
- Closes · 20 days leftBelow threshold - open competitionSME · VCSE suitable
Renewable Energy Study Commission
Erewash Borough Council · Local authority · East Midlands
Erewash Borough Council (EBC) have started work on a new Local Plan, which will be drawn up using the new National Planning Policy Framework (NPPF) 2026. The Planning Policy team is embarking on an evidence base gathering exercise so that a…
- Value
- £40k
- Term
- 3 months
- Submit via
- portal not identified
- Published
- #078e55
- Closes · 13 days leftBelow threshold - open competition
Cotham School - Invitation to Tender School Management Information System (MIS)
Cotham School · Education · delivery region not published
Cotham School are seeking a Software as a Service (SaaS) solution for the provision of a comprehensive Schools Management Information System (MIS). The primary objective of this tender is to procure a solution that enables schools to effici…
- Value
- £75k
- Term
- 3 years
- Submit via
- portal not identified
- Published
- #078e52
- Closes · 12 days leftOpen procedureFramework
Yorkshire Highway Alliance Road Markings Framework 2026-28
Leeds City Council · Local authority · delivery region not published
Implementation of road markings within Leeds and across the Yorkshire Highway Alliance
- Value
- £7.2mceiling, not a contract size
- Term
- 2 yearsup to 4 years with extensions
- Submit via
- Jaggaerlogin required
- Published
- #078e4f
- Closes · 20 days leftOpen procedure2 lotsSME suitable
The Provision of Servicing, Maintenance and Supply of Breathing Air Compressors
Cleveland Fire Authority · Police & fire · Nationwide (UK)
Cleveland Fire & Rescue Authority are conducting a Tender exercise on behalf of the participated services: Cleveland Fire & Rescue Authority, Durham & Darlington Fire & Rescue Service, Tyne & Wear Fire and Rescue Service and Northumberland …
- Value
- £210k
- Term
- 3 yearsup to 7 years with extensions
- Submit via
- In-tendlogin required
- Published
- #078e47
- Closes · 12 days leftBelow threshold - open competitionSME suitable
ERCF2509N 05 Waterloo Cottage
Conwy County Borough Council · Local authority · Wales (Cymru)
Conwy County Borough Council is seeking a Contractor to undertake the below works in the county of Conwy, postcode LL22 8RH. The existing concrete bag retaining wall supporting Waterloo Hill has deteriorated beyond repair and is at risk of …
- Value
- £275k
- Term
- 3 months
- Submit via
- Sell2Waleslogin required
- Published
- #078e24
- Closes · 9 days leftBelow threshold - open competition
Green Links Study, New Forest National Park
New Forest National Park Authority · South East England, South West England
The New Forest National Park Authority (NFNPA) is seeking a consultant to produce a four part study that examines the potential of connecting areas outside of the New Forest National Park (NFNP) boundary to land within and also connecting l…
- Value
- £100k
- Term
- 4 months
- Submit via
- In-tendlogin required
- Published
- #078e23
- Closes · 16 days leftOpen procedure
RUG - Implementation of the Rugby Town Centre Wayfinding Strategy
Rugby Borough Council · Local authority · West Midlands
The Borough Council is seeking the services of a suitably skilled and experienced Provider to design, supply and install a number of physical wayfinding items, as guided by and in compliance with the concepts of the Wayfinding Strategy (App…
- Value
- £530k
- Term
- 11 years
- Submit via
- portal not identified
- Published
- #078e21
- Closes · 13 days leftOpen procedureLight-touchSME · VCSE suitable
Emotional Mental Health and Wellbeing Service
Wolverhampton City Council · Local authority · West Midlands
The City of Wolverhampton Council, in partnership with Black Country Healthcare NHS Foundation Trust, is seeking a delivery partner(s) to provide the local Emotional Mental Health and Wellbeing (EMHWB) service. The EMHWB service will provid…
Likely replaces the contract held by Base 25 · ends
- Value
- £2.8m
- Term
- 3 yearsup to 5 years with extensions
- Submit via
- portal not identified
- Published
- #078e1d
- Closes · 9 days leftOpen procedureSME · VCSE suitable
CEFAS26-115 ITT for a Small Autonomous Underwater Vehicle
Cefas · Central government · Nationwide (UK)
Cefas currently uses hand deployable multi-parameter sondes (CTDs) for collecting water column data. With the advent of easy-to-use small AUVs we wish to supplement these programs with more autonomous data collection. We envision a platform…
- Value
- £100k
- Term
- 15 months
- Submit via
- Atamis (Health Family)login required
- Published
- #078e1c
- Closes · 18 days leftBelow threshold - open competitionSME · VCSE suitable
Provision of Digital Customer Engagement Platform
Codi Group Ltd · Wales (Cymru)
The Group intends to establish a contract for the procurement of a digital customer engagement platform. Codi have recently launched the new, innovative customer influence framework which resets how customers influence our business. The onl…
- Value
- £200k
- Term
- 2 yearsup to 4 years with extensions
- Submit via
- Sell2Waleslogin required
- Published
- #078e15
- Closes · 16 days leftBelow threshold - open competitionConcessionSME suitable
Ice Cream Concession, Towneley Park
Burnley Borough Council · Local authority · North West England
The Council invites tenders for the concession to sell ice cream, confectionery and cold drinks from mobile ice cream vans in Towneley Park, Burnley according to the terms and conditions outlined and the associated Licence Agreement. Tender…
Likely replaces the contract held by NIMRAH TRADING COMPANY LTD · ends
- Value
- £320k
- Term
- 5 years
- Submit via
- ProContract (Due North)login required
- Published
- #078e09
- Closes · 10 days leftOpen procedure2 lotsSME · VCSE suitable
Multi-Column Continuous Chromatography System and Automated Viral Inactivation System
Cell & Gene Therapy Catapult · delivery region not published
CGTC are looking for the purchase and installation of a multi-column chromatography system (MCCS) and a viral inactivation hardware system with related services e.g service, repair and maintenance contract, training and consumables for our …
- Value
- £1.6m
- Term
- 2 yearsup to 5 years with extensions
- Submit via
- Delta eSourcingpublic page
- Published
- #078e00
- Closes · 26 days leftBelow threshold - open competitionFrameworkSME · VCSE suitable
Highways Traffic Signals Framework
Nottingham City Council · Local authority · East Midlands
Nottingham City Council is seeking tenders from suitably experienced and qualified suppliers for inclusion on a Framework to deliver traffic signals work within the boundaries of Nottingham City Council. Subject to suitability, the Authorit…
Likely replaces the contract “CPU 5937 Highways Temporary Traffic Management Framework” · ends
- Value
- £2.0mceiling, not a contract size
- Term
- 4 years
- Submit via
- Panacealogin required
- Published
- #078dfd
- Closes · 2 days leftBelow threshold - open competitionLight-touchSME suitable
Homelessness Toolkits
Local Government Association · delivery region not published
The LGA have received a grant to commission the development of two toolkits delivered by one supplier focussed on homelessness prevention and temporary accommodation management following the publication of the MHCLG National Plan to End Hom…
- Value
- £65k
- Term
- 5 months
- Submit via
- Panacealogin required
- Published
- #078dfa
- Closes · 2 days leftBelow threshold - open competitionLight-touchSME suitable
Homelessness Toolkits
Local Government Association · delivery region not published
The LGA have received a grant to commission the development of two toolkits delivered by one supplier focussed on homelessness prevention and temporary accommodation management following the publication of the MHCLG National Plan to End Hom…
- Value
- £65k
- Term
- 5 months
- Submit via
- Panacealogin required
- Published
- #078df9
- Closes · 19 days leftBelow threshold - open competition2 lotsSME suitable
LBS Glazing Housing & Non-Housing
Leeds City Council · Local authority · Nationwide (UK)
To undertake various glazing works for Leeds Building Services
- Value
- £1.2m
- Term
- 2 yearsup to 3 years with extensions
- Submit via
- Jaggaerlogin required
- Published
- #078df8
- Closes · 10 days leftOpen procedure2 lotsSME · VCSE suitable
Multi-Column Continuous Chromatography System and Automated Viral Inactivation System
Cell & Gene Therapy Catapult · delivery region not published
CGTC are looking for the purchase and installation of a multi-column chromatography system (MCCS) and a viral inactivation hardware system with related services e.g service, repair and maintenance contract, training and consumables for our …
- Value
- £1.6m
- Term
- 2 yearsup to 5 years with extensions
- Submit via
- Delta eSourcingpublic page
- Published
- #078df6
- Closes · 12 days leftOpen procedure
The Provision and Maintenance of a Cell Sorter
MHRA · Central government · Nationwide (UK)
The Agency is looking to purchase a Cell Sorter as a replacement for Aria Cell Sorter (s/n P64828200097). This will include the purchase and maintenance of bespoke consumables and auxiliary equipment, if applicable. This cell sorter will su…
- Value
- £475k
- Term
- 3 yearsup to 7 years with extensions
- Submit via
- Atamis legacy domain (health-family.force.com)login required
- Published
- #078df1
- Closes · 13 days leftOpen procedure
Public Rights of Way: Supply of Gates & Fittings
Worcestershire County Council · Local authority · North East England, North West England, Yorkshire and the Humber, East Midlands, West Midlands, East of England
The Council is seeking a supplier to deliver a comprehensive range of Public Rights of Way (PRoW) gates, access structures, fittings and replacement components compliant with BS 5709:2018. The successful supplier will provide products to su…
- Value
- £350k
- Term
- 3 yearsup to 5 years with extensions
- Submit via
- In-tendlogin required
- Published
- #078df0
- Closes · 12 days leftBelow threshold - open competitionSME suitable
GLLM-ITT-64480 - 3G Pitch Upgrade - Rhos-On-Sea Campus
Grwp Llandrillo Menai · Wales (Cymru)
Grŵp Llandrillo Menai (GLLM) is seeking tenders from suitably qualified and experienced contractors for the upgrade of the existing 3G artificial grass football pitch at its Rhos-on-Sea Campus. The works will be undertaken in accordance wit…
- Value
- £331k
- Term
- 3 months
- Submit via
- Sell2Waleslogin required
- Published
- #078ded
- Closes · 17 days leftBelow threshold - open competitionSME suitable
Multi-Supplier Agreement for Design Services
LONDON METROPOLITAN UNIVERSITY · Education · North East England, North West England, Yorkshire and the Humber, East Midlands, West Midlands, East of England
1.1 The University regularly requires creative design support across a wide range of marketing, communications, recruitment, student engagement, events, and internal and external stakeholder activity. 1.2 While some design provision is deli…
- Value
- £132k
- Term
- 3 yearsup to 4 years with extensions
- Submit via
- portal not identified
- Published
- #078de1
- Closes · 9 days leftCompetitive flexible procedureSME suitable
GBC & WBC Fire Risk Assessments
Guildford Borough Council · Local authority · South East England
Guildford Borough Council and Waverley Borough Council require a consistent, competent and auditable fire risk assessment service across their housing and corporate property portfolios. The specification establishes the common minimum requi…
- Value
- £2.9m
- Term
- 3 yearsup to 5 years with extensions
- Submit via
- portal not identified
- Published
- #078ddf
- Closes · 18 days leftOpen procedure
Air Handling Unit PPMs
West Suffolk NHS Foundation Trust · Central government · delivery region not published
Provision of Air Handling Unit PPMs
- Value
- £160k
- Term
- 12 monthsup to 2 years with extensions
- Submit via
- Atamis legacy domain (health-family.force.com)login required
- Published
- #078dd9
- Closes · 104 days leftCompetitive flexible procedure5 lotsSME suitable
Education Recruitment Advertising and Resourcing Services
University of Reading · delivery region not published
For the supply of Education Recruitment Advertising, Marketing, Attraction and Student Recruitment Services
- Value
- £80m
- Term
- 2 yearsup to 4 years with extensions
- Submit via
- EU-Supply (CTM)public page
- Published
- #078dc8
- Closes · 8 days leftOpen procedureSME suitable
UKRI-6017-METIUS
UK Research and Innovation · Central government · South West England
The METIUS programme is a new infrastructure investment with a total UK funding allocation of £14.5 million. It aims to harness cutting-edge AI to improve the speed, relevance and accessibility of evidence synthesis for decision-makers tack…
- Value
- £167k
- Term
- 4 years
- Submit via
- UKRI eSourcinglogin required
- Published
- #078d9c
- Closes · 6 days leftBelow threshold - open competitionSME suitable
5521 - Cwm Ifor Primary School - Installation of Pedestrian Control Gate
Caerphilly County Borough Council · Local authority · Wales (Cymru)
You are invited to submit a tender for the Installation of access control to the front pedestrian gate at Cwm Ifor Primary School Caerphilly. The scope of the project is fully described in Appendix 1 but in summary the scope is: 1. Excavate…
- Value
- £35k
- Term
- 2 months
- Submit via
- ProContract (Due North)login required
- Published
- #078d99
- Closes · 6 days leftBelow threshold - open competitionSME suitable
5486 - Bryn Awel Primary School - Installation of Pedestrian Control Gate
Caerphilly County Borough Council · Local authority · Wales (Cymru)
You are invited to submit a tender for the automation of the main pedestrian gate at Bryn Awel Primary School Rhymey. The scope of the project is fully described in Appendix 1 but in summary the scope is: 1 Excavate Trench from Pedestrian g…
- Value
- £35k
- Term
- 24 days
- Submit via
- ProContract (Due North)login required
- Published
- #078d97
- Closes · 6 days leftCompetitive flexible procedureLight-touchUtilities5 lotsSME · VCSE suitable
Kent Integrated Family Domestic Abuse Service (KIFDAS)
Kent County Council · Local authority · South East England
The overarching objective of this commission is to bring together all related domestic abuse contracts which have previously been purchased in a fragmented way due to how funding has been announced and received over the existing contract te…
- Value
- £28m
- Term
- 3.5 yearsup to 7 years with extensions
- Submit via
- ProContract (Due North)login required
- Published
- #078d83
- Closes · 5 days leftBelow threshold - open competition
GSENZH Lead Financial Advisor
Cambridgeshire and Peterborough Combined Authority · Local authority · East of England
The GSENZH is seeking an appropriately qualified supplier to provide a named Lead Financial Adviser who will act as an intelligent client for GSENZH and its project stakeholders throughout the contract. It is expected that this role will be…
- Value
- Not published
- Term
- 4 monthsup to 16 months with extensions
- Submit via
- In-tendlogin required
- Published
- #078d69
- Closes · 14 days leftOpen procedureFramework
Port of Dover - IT Professional Resource Framework
Dover Harbour Board · delivery region not published
DHB require IT Professional Resource Framework partners to provide suitably qualified people on a Time Charge and Work Order basis. The Framework will primarily support the Client's IGNITE digital transformation programme, alongside other I…
- Value
- £3.0mceiling, not a contract size
- Term
- 4 years
- Submit via
- In-tendlogin required
- Published
- #078d66
- Closes · 12 days leftRestricted procedure
Wood Green Central Multi-Disciplinary Team
London Borough of Haringey · Local authority · Greater London
The Council is looking to employ a suitable contractor for the appointment of the Multi-Disciplinary Team (MDT) Lead Consultant to support Haringey Council in progressing the Wood Green Central Station Road sites to develop a coordinated, c…
- Value
- £1.5m
- Term
- 2 years
- Submit via
- London Construction Programmelogin required
- Published
- #078d60
- Closes · 4 days leftBelow threshold - open competitionSME · VCSE suitable
Tech support for the dev. of the PCF requirements of the NHS Supplier Roadmap
NHS England · Central government · delivery region not published
In 2021, the NHS Public Board approved a roadmap to drive supplier decarbonisation and support the achievement of the NHS Net Zero target. The 2028 milestone of this roadmap outlines new requirements to be introduced overseeing the provisio…
- Value
- £96k
- Term
- 4 months
- Submit via
- Atamis (Health Family)login required
- Published
- #078d5b
- Closes · 16 days leftOpen procedureUtilitiesSME suitable
Neville Hill 195 Heavy Maintenance Outline Designs
Northern Trains Ltd · Yorkshire and the Humber
Northern Trains Ltd, is a Train Operating Company (TOC) that operates passenger rail services in the North of England. Northern Trains Ltd is publishing this notice to establish a contract for the designs at Neville Hill for the 195 Mainten…
- Value
- £2.1m
- Term
- 10 months
- Submit via
- Delta eSourcingpublic page
- Published
- #078d5a
- Closes · 9 days leftOpen procedureSME · VCSE suitable
Prioritised Capital Improvements Programme - School Properties 2026-28
Cumberland Council · Local authority · North West England
This is a Procurement Re-wind in relation to UK4 Tender Notice identifier: 2026/S 000-084612. If you have previously submitted a tender under the existing process and wish to participate in the re-wound process, you will need to submit a re…
- Value
- £1.5m
- Term
- 2.5 years
- Submit via
- portal not identified
- Published
- #078d58
- Closes · 11 days leftBelow threshold - open competition
Market Intelligence and Document Search Platform
THE FINANCIAL REPORTING COUNCIL LIMITED · Central government · West Midlands, Greater London
BACKGROUND The Financial Reporting Council (FRC) regulates auditors, accountants and actuaries and sets the UK's Corporate Governance and Stewardship Codes. As the Competent Authority for audit in the UK, we set auditing and ethical standar…
- Value
- £100k
- Term
- 2 yearsup to 3 years with extensions
- Submit via
- portal not identified
- Published
- #078d56
- Closes · 11 days leftBelow threshold - open competition
Apheresis Expansion - Main Contractor
Guy's and St Thomas' NHS Foundation Trust · Central government · Greater London
Refurbishment of the Apheresis Suite at Guy's and St Thomas' NHS Foundation Trust. To create a modern, expanded 12 bed apheresis treatment facility within the Haematology Day Unit (HDU), 4th Floor Tower Wing, Guy's Hospital to provide faste…
- Value
- £2.6m
- Term
- 16 months
- Submit via
- Atamis legacy domain (health-family.force.com)login required
- Published
- #078d51
- Closes · 2 days leftBelow threshold - open competitionSME suitable
Economic analysis of access applications
Office of Rail and Road · Central government · Nationwide (UK)
This invitation to tender sets out ORR's requirement for consultants to carry out economic analysis in support of ORR's assessment of track access rights decisions for four access applications. ORR is responsible for regulating access to th…
- Value
- £95k
- Term
- 12 months
- Submit via
- portal not identified
- Published
- #078d4a
- Closes · 20 days leftBelow threshold - open competitionSME suitable
BA Compressor Maintenance 2026-2030
West Midlands Fire and Rescue Authority · Police & fire · West Midlands
A maintenance contract for WMFRA's breathing air compressors.
- Value
- £90k
- Term
- 2 yearsup to 4 years with extensions
- Submit via
- In-tendlogin required
- Published
- #078d49
- Closes · 13 days leftOpen procedureFramework5 lotsSME · VCSE suitable
Funding Solutions
Kent County Council · Local authority · delivery region not published
The Authority is seeking suitably qualified Candidates to bid to enter into Framework Agreements with the Authority to provide the Services to Customers under Call-Off Contracts Potentially seeking to provide: The Services Lessors are invit…
- Value
- £400mceiling, not a contract size
- Term
- 4 years
- Submit via
- Delta eSourcingpublic page
- Published
- #078d47
- Closes · 20 days leftOpen procedureSME suitable
Aspire Academy Trust - Provision of HR and Payroll System
Aspire Academy Trust · South West England
This tender opportunity has been issued by Aspire Academy Trust (the Trust), and Tenderers are invited to tender for the provision of an integrated Human Resources and Payroll system, with the capability to support a fully managed payroll s…
- Value
- £450k
- Term
- 3 yearsup to 6 years with extensions
- Submit via
- EU-Supply (CTM)public page
- Published
- #078d44
- Closes · 18 days leftOpen procedure
Scottish Approach to Change Evaluation and Learning Partner
Healthcare Improvement Scotland · Scotland
We are seeking to commission a suitably qualified and experienced provider to design and deliver a robust, independent evaluation of the Scottish Approach to Change. The evaluation should provide objective challenge, learning, reflection an…
- Value
- Not published
- Term
- 15 months
- Submit via
- Public Contracts Scotlandlogin required
- Published
- #078d41
- Closes · 13 days leftOpen procedure
Key Management System
THE PIRBRIGHT INSTITUTE · delivery region not published
This opportunity (“Contract”) is for a single supplier to supply, install, service and maintain a new replacement Key Management System to the Institute. The project is to replace the current, end-of-life system on a like for like basis i.e…
- Value
- £234k
- Term
- 10 months
- Submit via
- In-tendlogin required
- Published
- #078d3b