Homepage
Searching for patents
Patent knowledge
Access our patent databases and search tools.
Go to overview
Overview

Technical information

Overview

Espacenet - patent search

European Publication Server

EP full-text search

Legal information

Overview

European Patent Register

European Patent Bulletin

European Case Law Identifier sitemap

Third-party observations

Business information

Overview

PATSTAT

IPscore

Technology insight reports

Data

Overview

Technology Intelligence Platform

Linked open EP data

Bulk data sets

Web services

Coverage, codes and statistics

Technology platforms

Overview

Digital agriculture

Plastics in transition

Water innovation

Space innovation

Technologies combatting cancer

Firefighting technologies

Clean energy technologies

Fighting coronavirus

Helpful resources

Overview

First time here?

Asian patent information

Patent information centres

Patent Translate

Patent Knowledge News

Business and statistics

Unitary Patent information in patent knowledge
Image

Technology insight report on digital agriculture
Applying for a patent
Applying for a patent
Practical information on filing and grant procedures.
Go to overview
Overview

European route

Overview

European Patent Guide

Oppositions

Oral proceedings

Appeals

Unitary Patent & Unified Patent Court

National validation

Request for extension/validation

International route (PCT)

Overview

Euro-PCT Guide – PCT procedure at the EPO

EPO decisions and notices

PCT provisions and resources

Extension/validation request

Reinforced partnership programme

Accelerating your PCT application

Patent Prosecution Highway (PPH)

Training and events

National route

Find a professional representative

MyEPO services

Overview

Understand our services

Get access

File with us

Interact with us on your files

Online Filing & fee payment outages

Forms

Overview

Request for examination

Fees

Overview

European fees (EPC)

International fees (PCT)

Unitary Patent fees (UP)

Fee payment and refunds

Warning

Fee Assistant

Fee reductions and compensation
Find out how the Unitary Patent can enhance your IP strategy
Law & practice
Law & practice
European patent law, the Official Journal and other legal texts.
Go to overview
Overview

Legal texts

Overview

European Patent Convention

Official Journal

Guidelines

Extension / validation system

London Agreement

National law relating to the EPC

Unitary patent system

National measures relating to the Unitary Patent

Court practices

Overview

European Patent Judges' Symposium

User consultations

Overview

Ongoing consultations

Completed consultations

Substantive patent law harmonisation

Overview

The Tegernsee process

Group B+

Convergence of practice

Options for representatives
Image

Keep up with key aspects of selected BoA decisions with our monthly "Abstracts of decisions”
News & events
News & events
Our latest news, podcasts and events, including the European Inventor Award.
Go to overview
Overview

News

Events

European Inventor Award

Overview

About the award

Categories and prizes

Meet the finalists

Nominations

European Inventor Network

The 2024 event

Young Inventors Prize

Overview

About the prize

Nominations

The world, reimagined

The 2025 event

Press centre

Overview

Patent Index and statistics

Search in press centre

Background information

Copyright

Press contacts

Call back form

Email alert service

Innovation and patenting in focus

Overview

CodeFest

Green tech in focus

Research institutes

Lifestyle

Space and satellites

The future of medicine

Materials science

Mobile communications

Biotechnology

Patent classification

Digital technologies

The future of manufacturing

Books by EPO experts

"Talk innovation" podcast
From ideas to inventions: tune into our podcast for the latest in tech and IP
Learning
Learning
The European Patent Academy – the point of access to your learning
Go to overview
Overview

Learning activities and paths

Overview

Learning activities

Learning paths

EQE and EPAC

Overview

EQE - European qualifying examination

EPAC - European patent administration certification

CSP – Candidate Support Programme

Learning resources by area of interest

Overview

Patent granting

Technology transfer and dissemination

Patent enforcement and litigation

Learning resources by profile

Overview

Business and IP managers

EQE and EPAC Candidates

Judges, lawyers and prosecutors

National offices and IP authorities

Patent attorneys and paralegals

Universities, research centres and technology transfer centres (TTOs)
Image

Have a look at the extensive range of learning opportunities in the European Patent Academy training catalogue
About us
About us
Find out more about our work, values, history and vision
Go to overview
Overview

The EPO at a glance

50 years of the EPC

Overview

Official celebrations

Member states’ video statements

50 Leading Tech Voices

Athens Marathon

Kids’ collaborative art competition

Legal foundations and member states

Overview

Legal foundations

Member states of the European Patent Organisation

Extension states

Validation states

Administrative Council and subsidiary bodies

Overview

Communiqués

Calendar

Documents and publications

Administrative Council

Principles & strategy

Overview

Our mission, vision, values and corporate policy

Strategic Plan 2028

Towards a New Normal

Leadership & management

Overview

President António Campinos

Management Advisory Committee

Sustainability at the EPO

Overview

Environmental

Social

Governance and Financial sustainability

Services & activities

Overview

Our services & structure

Quality

Consulting our users

European and international co-operation

European Patent Academy

Ombuds Office

Reporting wrongdoing

Observatory on Patents and Technology

Overview

Technologies

Innovation actors

Policy and funding

Tools

About the Observatory

Procurement

Overview

Procurement forecast

Doing business with the EPO

Procurement procedures

Sustainable Procurement Policy

About eTendering and electronic signatures

Procurement portal

Invoicing

General conditions

Archived tenders

Transparency portal

Overview

General

Human

Environmental

Organisational

Social and relational

Economic

Governance

Statistics and trends

Overview

Statistics & Trends Centre

Patent Index 2024

EPO Data Hub

Clarification on data sources

History

Overview

1970s

1980s

1990s

2000s

2010s

2020s

Art collection

Overview

The collection

Let's talk about art

Artists

Media library

What's on

Publications

Contact

Culture Space A&T 5-10

"Long Night"
Image

Track the latest tech trends with our Patent Index

Search

en de fr

Language selection
English
Deutsch
Français

Main navigation

Homepage
- Go back
- New to patents
New to patents
Searching for patents
- Go back
- Overview
- Technical information
  - Go back
  - Overview
  - Espacenet - patent search
    - Go back
    - Overview
    - National patent office databases
    - Global Patent Index (GPI)
    - Release notes
  - European Publication Server
    - Go back
    - Overview
    - Release notes
    - Cross-reference index for Euro-PCT applications
    - EP authority file
    - Help
  - EP full-text search
- Legal information
  - Go back
  - Overview
  - European Patent Register
    - Go back
    - Overview
    - Release notes archive
    - Register documentation
      - Go back
      - Overview
      - Deep link data coverage
      - Federated Register
      - Register events
  - European Patent Bulletin
    - Go back
    - Overview
    - Download Bulletin
    - EP Bulletin search
    - Help
  - European Case Law Identifier sitemap
  - Third-party observations
- Business information
  - Go back
  - Overview
  - PATSTAT
  - IPscore
    - Go back
    - Release notes
  - Technology insight reports
- Data
  - Go back
  - Overview
  - Technology Intelligence Platform
  - Linked open EP data
  - Bulk data sets
  - Web services
    - Go back
    - Overview
    - Open Patent Services (OPS)
    - European Publication Server web service
  - Coverage, codes and statistics
    - Go back
    - Weekly updates
    - Updated regularly
- Technology platforms
  - Go back
  - Overview
  - Quantum technologies
    - Go back
    - Communication
    - Computing
    - Sensing
  - Digital agriculture
    - Go back
    - Overview
    - Plant agriculture
    - Artificial growth conditions
    - Livestock management
    - Supporting technologies
  - Plastics in transition
    - Go back
    - Overview
    - Plastics waste recovery
    - Plastics waste recycling
    - Alternative plastics
  - Innovation in water technologies
    - Go back
    - Overview
    - Clean water
    - Protection from water
  - Space innovation
    - Go back
    - Overview
    - Cosmonautics
    - Space observation
  - Technologies combatting cancer
    - Go back
    - Overview
    - Prevention and early detection
    - Diagnostics
    - Therapies
    - Wellbeing and aftercare
  - Firefighting technologies
  - Clean energy technologies
  - Fighting coronavirus
    - Go back
    - Overview
    - Vaccines and therapeutics
    - Diagnostics and analytics
      - Go back
      - Overview
      - Protein and nucleic acid assays
      - Analytical protocols
    - Informatics
      - Go back
      - Overview
      - Bioinformatics
      - Healthcare informatics
    - Technologies for the new normal
    - Inventors against coronavirus
- Helpful resources
  - Go back
  - Overview
  - First time here?
    - Go back
    - Overview
    - Basic definitions
    - Patent classification
      - Go back
      - Overview
      - Cooperative Patent Classification (CPC)
    - Patent families
      - Go back
      - Overview
      - DOCDB simple patent family
      - INPADOC extended patent family
    - Legal event data
      - Go back
      - Overview
      - INPADOC classification scheme
  - Asian patent information
    - Go back
    - Overview
    - China (CN)
      - Go back
      - Overview
      - Facts and figures
      - Grant procedure
      - Numbering system
      - Useful terms
      - Searching in databases
    - Taiwan, Province of China (TW)
      - Go back
      - Overview
      - Grant procedure
      - Numbering system
      - Useful terms
      - Searching in databases
    - India (IN)
      - Go back
      - Overview
      - Facts and figures
      - Grant procedure
      - Numbering system
    - Japan (JP)
      - Go back
      - Overview
      - Facts and figures
      - Grant procedure
      - Numbering system
      - Useful terms
      - Searching in databases
    - Korea (KR)
      - Go back
      - Overview
      - Facts and figures
      - Grant procedure
      - Numbering system
      - Useful terms
      - Searching in databases
    - Useful links
  - Patent information centres (PATLIB)
  - Patent Translate
  - Patent Knowledge News
  - Business and statistics
  - Unitary Patent information in patent knowledge
Applying for a patent
- Go back
- Overview
- European route
  - Go back
  - Overview
  - European Patent Guide
  - Oppositions
  - Oral proceedings
    - Go back
    - Oral proceedings calendar
  - Appeals
  - Unitary Patent & Unified Patent Court
    - Go back
    - Overview
    - Unitary Patent
    - Unified Patent Court
  - National validation
  - Extension/validation request
- International route
  - Go back
  - Overview
  - Euro-PCT Guide
  - Entry into the European phase
  - Decisions and notices
  - PCT provisions and resources
  - Extension/validation request
  - Reinforced partnership programme
  - Accelerating your PCT application
  - Patent Prosecution Highway (PPH)
    - Go back
    - Patent Prosecution Highway (PPH) programme outline
  - Training and events
- National route
- MyEPO services
  - Go back
  - Overview
  - Understand our services
    - Go back
    - Overview
    - Exchange data with us using an API
      - Go back
      - Release notes
  - Get access
    - Go back
    - Overview
    - Release notes
  - File with us
    - Go back
    - Overview
    - What if our online filing services are down?
    - Release notes
  - Interact with us on your files
    - Go back
    - Release notes
  - Online Filing & fee payment outages
- Fees
  - Go back
  - Overview
  - European fees (EPC)
    - Go back
    - Overview
    - Decisions and notices
  - International fees (PCT)
    - Go back
    - Reduction in fees
    - Fees for international applications
    - Decisions and notices
    - Overview
  - Unitary Patent fees (UP)
    - Go back
    - Overview
    - Decisions and notices
  - Fee payment and refunds
  - Warning
  - Fee Assistant
  - Fee reductions and compensation
    - Go back
    - Fee support scheme insights
- Forms
  - Go back
  - Overview
  - Request for examination
- Find a professional representative
Law & practice
- Go back
- Overview
- Legal texts
  - Go back
  - Overview
  - European Patent Convention
    - Go back
    - Overview
    - Archive
      - Go back
      - Overview
      - Documentation on the EPC revision 2000
        
        Go back
        
        Overview
        
        Diplomatic Conference for the revision of the EPC
        
        Travaux préparatoires
        
        New text
        
        Transitional provisions
        
        Implementing regulations to the EPC 2000
        
        Rules relating to Fees
        
        Ratifications and accessions
      - Travaux Préparatoires EPC 1973
  - Official Journal
  - Guidelines
  - Extension / validation system
  - London Agreement
  - National law relating to the EPC
    - Go back
    - Overview
    - Archive
  - Unitary Patent system
    - Go back
    - Travaux préparatoires to UP and UPC
  - National measures relating to the Unitary Patent
  - International treaties
- Court practices
  - Go back
  - Overview
  - European Patent Judges' Symposium
- User consultations
  - Go back
  - Overview
  - Ongoing consultations
  - Completed consultations
- Substantive patent law harmonisation
  - Go back
  - Overview
  - The Tegernsee process
  - Group B+
- Convergence of practice
- Options for representatives
News & events
- Go back
- Overview
- News
- Events
- European Inventor Award
  - Go back
  - Overview
  - About the award
  - Categories and prizes
  - Meet the inventors
  - Nominations
  - European Inventor Network
    - Go back
    - Overview
    - 2026 activities
    - 2025 activities
    - 2024 activities
    - Rules and criteria
    - FAQ
  - The 2024 event
- Young Inventors Prize
  - Go back
  - Overview
  - About the prize
  - Nominations
  - The world, reimagined
  - The 2025 event
- Press centre
  - Go back
  - Overview
  - Patent Index and statistics
  - Search in press centre
  - Background information
  - Copyright
  - Press contacts
  - Call back form
  - Email alert service
- In focus
  - Go back
  - Overview
  - CodeFest
  - Green tech in focus
  - Research institutes
  - Lifestyle
  - Space and satellites
    - Go back
    - Overview
    - Patents and space technologies
  - Healthcare
  - Materials science
    - Go back
    - Overview
    - Nanotechnology
  - Mobile communications
  - Biotechnology
    - Go back
    - Overview
    - Red, white or green
    - The role of the EPO
    - What is patentable?
    - Biotech inventors
  - Classification
    - Go back
    - Overview
    - Nanotechnology
    - Climate change mitigation technologies
      - Go back
      - Overview
      - External partners
      - Updates on Y02 and Y04S
  - Digital technologies
    - Go back
    - Overview
    - About ICT
    - Hardware and software
    - Artificial intelligence
    - Fourth Industrial Revolution
  - Additive manufacturing
    - Go back
    - Overview
    - About AM
    - AM innovation
  - Books by EPO experts
- Podcast
Learning
- Go back
- Overview
- Learning activities and paths
  - Go back
  - Overview
  - Learning activities: types and formats
  - Learning paths
- EQE and EPAC
  - Go back
  - Overview
  - EQE - European Qualifying Examination
    - Go back
    - Overview
    - Compendium
      - Go back
      - Overview
      - Paper F
      - Paper A
      - Paper B
      - Paper C
      - Paper D
      - Pre-examination
    - Candidates successful in the European qualifying examination
    - Archive
  - EPAC - European patent administration certification
  - CSP – Candidate Support Programme
- Learning resources by area of interest
- Learning resources by profile
  - Go back
  - Overview
  - Business and IP managers
    - Go back
    - Overview
    - Innovation case studies
    - Inventor's handbook
    - Best of search matters
    - Support for high-growth technology businesses
  - EQE and EPAC Candidates
  - Judges, lawyers and prosecutors
  - National offices and IP authorities
  - Patent attorneys and paralegals
  - Universities, research centres and TTOs
    - Go back
    - Overview
    - Modular IP Education Framework (MIPEF)
    - Pan-European Seal Young Professionals Programme
      - Go back
      - Overview
      - For universities
        
        Go back
        
        Overview
        
        IP education resources
        
        Participating universities
    - IP Teaching Kit
      - Go back
      - Overview
      - Download modules
    - Intellectual property course design manual
    - PATLIB Knowledge Transfer to Africa
      - Go back
      - Core activities
      - Stories and insights
About us
- Go back
- Overview
- The EPO at a glance
- 50 years of the EPC
  - Go back
  - Official celebrations
  - Overview
  - Member states’ video statements
    - Go back
    - Albania
    - Austria
    - Belgium
    - Bulgaria
    - Croatia
    - Cyprus
    - Czech Republic
    - Denmark
    - Estonia
    - Finland
    - France
    - Germany
    - Greece
    - Hungary
    - Iceland
    - Ireland
    - Italy
    - Latvia
    - Liechtenstein
    - Lithuania
    - Luxembourg
    - Malta
    - Monaco
    - Montenegro
    - Netherlands
    - North Macedonia
    - Norway
    - Poland
    - Portugal
    - Romania
    - San Marino
    - Serbia
    - Slovakia
    - Slovenia
    - Spain
    - Sweden
    - Switzerland
    - Türkiye
    - United Kingdom
  - 50 Leading Tech Voices
  - Athens Marathon
  - Kids’ collaborative art competition
- Legal foundations and member states
  - Go back
  - Overview
  - Legal foundations
  - Member states
    - Go back
    - Overview
    - Member states by date of accession
  - Extension states
  - Validation states
- Administrative Council and subsidiary bodies
  - Go back
  - Overview
  - Communiqués
    - Go back
    - 2024
    - Overview
    - 2023
    - 2022
    - 2021
    - 2020
    - 2019
    - 2018
    - 2017
    - 2016
    - 2015
    - 2014
    - 2013
  - Calendar
  - Documents and publications
  - Administrative Council
    - Go back
    - Overview
    - Composition
    - Representatives
    - Rules of Procedure
    - Board of Auditors
    - Secretariat
    - Council bodies
- Principles & strategy
  - Go back
  - Overview
  - Mission, vision, values & corporate policy
  - Strategic Plan 2028
  - Towards a New Normal
  - Data protection & privacy notice
- Leadership & management
  - Go back
  - Overview
  - About the President
  - Management Advisory Committee
- Sustainability at the EPO
  - Go back
  - Overview
  - Environmental
    - Go back
    - Overview
    - Inspiring environmental inventions
  - Social
    - Go back
    - Overview
    - Inspiring social inventions
  - Governance and Financial sustainability
    - Go back
    - Integrated management at the EPO
- Procurement
  - Go back
  - Overview
  - Procurement forecast
  - Doing business with the EPO
  - Procurement procedures
  - Dynamic Purchasing System (DPS) publications
  - Sustainable Procurement Policy
  - About eTendering
  - Invoicing
  - Procurement portal
    - Go back
    - Overview
    - e-Signing contracts
  - General conditions
  - Archived tenders
- Services & activities
  - Go back
  - Overview
  - Our services & structure
  - Quality
    - Go back
    - Overview
    - Foundations
      - Go back
      - Overview
      - European Patent Convention
      - Guidelines for examination
      - Our staff
    - Enabling quality
      - Go back
      - Overview
      - Prior art
      - Classification
      - Tools
      - Processes
    - Products & services
      - Go back
      - Overview
      - Search
      - Examination
      - Opposition
      - Continuous improvement
    - Quality through networking
      - Go back
      - Overview
      - User engagement
      - Co-operation
      - User satisfaction survey
      - Stakeholder Quality Assurance Panels
    - Patent Quality Charter
    - Quality Action Plan
    - Quality dashboard
    - Statistics
      - Go back
      - Overview
      - Search
      - Examination
      - Opposition
  - Consulting our users
    - Go back
    - Overview
    - Standing Advisory Committee before the EPO (SACEPO)
      - Go back
      - Overview
      - Objectives
      - SACEPO and its working parties
      - Meetings
      - Single Access Portal – SACEPO Area
    - Surveys
  - Our user service charter
  - European and international co-operation
    - Go back
    - Overview
    - Co-operation with member states
      - Go back
      - Overview
    - Bilateral co-operation with non-member states
      - Go back
      - Overview
      - Validation system
      - Reinforced Partnership programme
    - Multilateral international co-operation with IP offices and organisations
    - Co-operation with international organisations outside the IP system
  - European Patent Academy
    - Go back
    - Overview
    - Partners
  - Ombuds Office
  - Reporting wrongdoing
- Observatory on Patents and Technology
  - Go back
  - Overview
  - Technologies
    - Go back
    - Overview
    - Innovation against cancer
    - Assistive robotics
    - Energy enabling technologies
      - Go back
      - Overview
      - Publications
    - Energy generation technologies
    - Water technologies
    - Plastics in transition
    - Space technologies
    - Digital agriculture
    - Quantum technologies
  - Innovation actors
    - Go back
    - Overview
    - Startups and SMEs
      - Go back
      - Overview
      - Publications
      - Events
    - Research universities and public research organisations
    - Women inventors
  - Policy and funding
    - Go back
    - Overview
    - Financing innovation programme
    - Patents and standards
      - Go back
      - Overview
      - Publications
      - Patent standards explorer
  - Observatory tools
    - Go back
    - Overview
    - Deep Tech Finder
    - Digital Library on Innovation
      - Go back
      - Overview
      - Become a contributor to the Digital Library
  - About the Observatory
    - Go back
    - Overview
    - Work plan
    - Chief Economist
      - Go back
      - Overview
      - Economic studies
      - Academic Research Programme
        
        Go back
        
        Overview
        
        Current research projects
        
        Completed research projects
    - Collaboration with European actors
- Transparency portal
  - Go back
  - Overview
  - General
    - Go back
    - Overview
    - Annual Review 2024
    - Annual Review 2023
    - Annual Review 2022
  - Human
  - Environmental
  - Organisational
  - Social and relational
  - Economic
  - Governance
- Statistics and trends
  - Go back
  - Overview
  - Statistics & Trends Centre
  - Patent Index 2024
    - Go back
    - Insight into computer technology and AI
    - Insight into clean energy technologies
    - Statistics and indicators
      - Go back
      - European patent applications
        
        Go back
        
        Key trend
        
        Origin
        
        Top 10 technical fields
        
        Go back
        
        Computer technology
        
        Electrical machinery, apparatus, energy
        
        Digital communication
        
        Medical technology
        
        Transport
        
        Measurement
        
        Biotechnology
        
        Pharmaceuticals
        
        Other special machines
        
        Organic fine chemistry
        
        All technical fields
      - Applicants
        
        Go back
        
        Top 50
        
        Categories
        
        Women inventors
      - Granted patents
        
        Go back
        
        Key trend
        
        Origin
        
        Designations
  - Data to download
  - EPO Data Hub
  - Clarification on data sources
- History
  - Go back
  - Overview
  - 1970s
  - 1980s
  - 1990s
  - 2000s
  - 2010s
  - 2020s
- Art collection
  - Go back
  - Overview
  - The collection
  - Let's talk about art
  - Artists
  - Media library
  - What's on
  - Publications
  - Contact
  - Culture Space A&T 5-10
    - Go back
    - Overview
    - Catalyst lab & Deep vision
    - The European Patent Journey
    - Sustaining life. Art in the climate emergency
    - Next generation statements
    - Open storage
    - Cosmic bar
  - "Long Night"
Boards of Appeal
- Go back
- Overview
- Decisions of the Boards of Appeal
  - Go back
  - Overview
  - Recent decisions
  - Selected decisions
- Information from the Boards of Appeal
- Procedure
- Oral proceedings
- About the Boards of Appeal
  - Go back
  - Overview
  - President of the Boards of Appeal
  - Enlarged Board of Appeal
  - Technical Boards of Appeal
  - Legal Board of Appeal
  - Disciplinary Board of Appeal
  - Presidium
    - Go back
    - Overview
- Code of Conduct
- Business distribution scheme
  - Go back
  - Overview
  - Technical boards of appeal by IPC in 2026
  - Archive
- Annual list of cases
- Communications
- Annual reports
  - Go back
  - Overview
- Publications
  - Go back
  - Abstracts of decisions
- Case Law of the Boards of Appeal
  - Go back
  - Overview
  - Archive
- Diversity and Inclusion
Service & support
- Go back
- Overview
- Website updates
- Availability of online services
  - Go back
  - Overview
- FAQ
  - Go back
  - Overview
- Publications
- Ordering
  - Go back
  - Overview
  - Patent Knowledge Products and Services
  - Terms and conditions
    - Go back
    - Overview
    - Patent information products
    - Bulk data sets
    - Open Patent Services (OPS)
    - Fair use charter
- Procedural communications
- Useful links
- Contact us
  - Go back
  - Overview
  - Filing options
  - Locations
- Subscription centre
  - Go back
  - Overview
  - Subscribe
  - Change preferences
  - Unsubscribe
- Official holidays
- Glossary
- RSS feeds

1. Time limits and loss of rights resulting from failure to respond within a time limit

Home
Legal texts
Guidelines for Examination
Table of Contents
Part E
Chapter VIII
1. Time limits and loss of rights resulting from failure to respond within a time limit
1.6 Extension of a time limit

Print

Facebook Twitter Linkedin Email

1.6 Extension of a time limit

Overview

1.6 Extension of a time limit

A revised version of this publication entered into force.

1.6.1 Extension of time limits set by the EPO under Rule 132

1.6.2 Extension of periods under Rule 134

Previous

Next

Show modifications

Footer - Service & support

Service & support

Footer - More links

Jobs & careers
Press centre
Single Access Portal
Procurement
Boards of Appeal

European Patent Office

EuropeanPatentOffice

European Patent Office

EPO Procurement

Footer

Legal notice
Terms of use
Data protection and privacy
Accessibility