EPC Check by Postcode: Quick, Easy and Free in the UK

epc check by postcode

Greetings, UK dwellers! Are you keen to get a handle on your property’s energy efficiency? With a simple EPC check by postcode, you can unlock valuable insights into your home’s energy performance, all at no cost. An Energy Performance Certificate (EPC) is more than just an official document; it’s a goldmine of information that lets you gauge how energy-efficient your dwelling is, potentially influencing both its market value and your utility bills.

Embarking on a free EPC check is a breeze, and it holds the key to understanding your energy efficiency rating by postcode. Whether you’re a homeowner eyeing potential improvements or a renter curious about your living space’s green credentials, an EPC offers clarity and guidance toward a more sustainable lifestyle. So, why not take advantage of this cost-free opportunity to assess and enhance the energy efficiency of your UK property?

Key Takeaways

  • EPC checks by postcode offer a quick snapshot of your property’s energy efficiency.
  • Understanding your UK energy performance certificate can lead to a more eco-friendly home.
  • Discovering your energy efficiency rating by postcode is completely free of charge.
  • A higher EPC rating can enhance your property’s appeal to buyers and renters alike.
  • Easy access to EPC information encourages UK residents to pursue energy-efficient upgrades.
  • An EPC is a valuable tool for anyone looking to save on energy costs in the long term.

Understanding Energy Performance Certificates in the UK

At the heart of discussions around energy efficiency in the United Kingdom, the Energy Performance Certificate (EPC) surfaces as a pivotal factor in influencing how homeowners and renters engage with their living spaces. Let’s delve into what an EPC entails and uncover why it’s essential in today’s environmentally conscious and economically savvy society.

What is an EPC?

An EPC is an assessment that details the energy efficiency of a property on a scale ranging from A (very efficient) to G (inefficient). Put simply, it answers the question: “What is an EPC?” Through an EPC, homeowners and prospective buyers can ascertain how much it will cost to heat and power a property, coupled with recommendations on how to improve its efficiency.

An EPC is not only a measure of current energy performance but also offers a valuable forecast for potential efficiency after recommended improvements are made. This forecast has a powerful influence on a property’s appeal, as energy-efficient homes are increasingly sought-after due to their lower carbon footprint and reduced utility expenses. But beyond practical advantages, EPCs carry legal weight, being a necessary requirement for any property sale or rent in the United Kingdom.

Energy Performance Certificate Illustration

The Importance of EPC for Homeowners and Renters

Why does an EPC matter to you, whether you own a home or are renting one? The answers lie in the various roles an EPC plays in property transactions and management:

  • It equips homeowners with the knowledge to enhance the energy efficiency of their property, turning potential improvements into real cost savings and increased market value.
  • For renters, an EPC gives insight into the long-term energy costs of living in a property, thus affecting their rental decisions and potentially giving them leverage to request necessary energy efficiency improvements.

Given the UK’s commitment to reducing carbon emissions, EPCs also serve a larger purpose by encouraging property owners and tenants to contribute positively to the nation’s environmental goals. It isn’t merely about compliance; it’s about participating in a more sustainable future.

Stakeholder Role of EPC Benefits
Homeowners Required for sale or rent Higher property value, cost savings on energy bills
Renters Influence on rental choices Empowers negotiations for improved efficiency
Environment Encourages energy-efficient living Contributes to national carbon emission reduction goals

As we progress through this exploration, keep in mind that the significance of the EPC for renters and homeowners alike is multi-faceted; from legal obligations to personal and societal benefits. It’s clear that an EPC checks the energy performance of a property whilst also checking the right boxes for economic and environmental mindfulness.

Remember, an Environmental Performance Certificate isn’t just a document — it’s a roadmap to a more energy-efficient and cost-effective future.

Why You Need to Check Your EPC Rating

Comprehending the EPC importance is pivotal for UK residents aiming to stay abreast of their properties’ energy credentials. Engaging in an EPC rating check isn’t just recommended; it’s a practice intertwined with a series of obligations and benefits. Below are cogent arguments for why check EPC rating ought to be on your to-do list.

Legal compliance is one of the undeniable reasons. Landlords, for instance, are legally required to possess a valid EPC before leasing their property. Without it, they risk facing penalties, underscoring the EPC’s role in the UK’s legal framework for rental properties.

EPC Rating Check Importance

From an economic standpoint, homeowners stand to gain remarkably by staying informed about their EPC ratings. Those looking to sell or rent out their property find that a favourable EPC rating can elevate the property’s desirability, potentially leading to a quicker sale or rental at a more advantageous price. It’s a primary motivation for why homeowners should proactively conduct an EPC rating check.

Aside from financial and legal incentives, there exists an intrinsic motive centred on sustainable living. With increased awareness of environmental issues, an EPC rating check can be the first step towards reducing a home’s carbon footprint, making a tangible contribution to a greener planet.

An EPC rating is not merely a statutory requirement but is a catalyst for fostering environmentally conscious lifestyles and enhancing economic benefits for property owners.

Reason for EPC Check Description Impact
Legal Obligation Landlords must have a valid EPC to rent out their property legally. Avoid legal ramifications and fines.
Market Appeal Properties with good EPC ratings are more attractive to buyers and tenants. Potentially faster and more lucrative property transactions.
Eco-friendly Incentive Identifies how properties can be more energy-efficient. Promotes sustainable living and contributes to reducing carbon emissions.

Given the array of compelling reasons to carry out an EPC rating check, it’s apparent that the process bears significance not solely due to compliance but beyond, influencing fiscal considerations and nurturing a heartfelt commitment to sustainability.

How to Conduct an EPC Check by Postcode

Investigating your home’s energy performance is now simpler than ever with the advent of online services. Conducting an EPC check by postcode ensures that you have all the necessary information about your property’s energy efficiency at your fingertips. This step-by-step guide will take you through the process of using an online EPC checking guide, helping you to access the valuable data contained within an Energy Performance Certificate.

Step-by-Step Guide to Online EPC Checking

Whether you’re considering selling your home, renting it out, or simply looking to improve its energy efficiency, the following online procedure is designed to be user-friendly:

  1. Visit the EPC Register: Start by navigating to the official EPC Register website, which is the central database for all EPC records in the UK.
  2. Enter Your Postcode: In the dedicated search area, type in the postcode of the property for which you require an EPC check.
  3. Select Your Property: From the list of addresses displayed, find and select your property to view its EPC report.
  4. Review the EPC Certificate: The EPC report will provide a wealth of information including the property’s energy efficiency ratings and potential savings. Take your time to review all the details.
  5. Download or Print: For future reference, you may download or print a copy of the EPC certificate.

Performing an EPC check in this manner should take no more than a few minutes and can be accomplished by anyone, regardless of technical skill level. The process provides quick, easy, and direct access to a property’s energy information.

Step Action Expected Outcome
1 Access the EPC Register online Entry into the official national database of EPC records
2 Input the property’s postcode A list of properties linked to that postcode
3 Select the correct address Display of the specific EPC report for the chosen property
4 Examine the EPC details Understanding of the property’s energy performance
5 Save the certificate information A physical or digital copy of the EPC for your records

With the rise of digital platforms, checking your property’s EPC has never been more accessible. Employing this online method circumvents the need for physical appointments, making the process of conducting an EPC check by postcode a task that can be accomplished from the comfort of your own home.

Efficiency is key when it comes to managing your home’s energy use, and a thorough understanding of your property’s EPC can lead to significant savings and enhanced home value. Therefore, the importance of an EPC check should not be understated.

By taking advantage of online EPC checking tools, property owners can ensure their homes are evaluated accurately, providing a clear path to energy efficiency improvements that can benefit both the environment and the pocketbook.

The Benefits of Using a Free EPC Checker by Postcode

The landscape of property management in the UK is increasingly digital, and the ability to easily access a property’s Energy Performance Certificate (EPC) has become a pivotal aspect of responsible homeownership. A free EPC checker by postcode is a critical tool offering numerous advantages for property owners looking to gain insights into their energy usage, ultimately leading to cost savings and increased energy efficiency. Let’s explore the myriad of benefits that an EPC checker offers.

In today’s eco-conscious society, having the ability to understand and improve the energy performance of your property can have substantial implications, from cost savings to contributing to larger environmental objectives. Here are the key benefits of an EPC checker:

  • Instantaneous Results: By simply entering your postcode, you receive immediate access to the EPC details of your property.
  • User-Friendly Interface: These checkers are designed for ease of use, ensuring that everyone can navigate the process with little to no difficulty.
  • No Cost Involved: As the service is complimentary, it presents an opportunity for all property owners, regardless of their budget, to engage with their property’s energy information.

Additionally, performing an EPC check can be an eye-opener, guiding homeowners towards making more energy-conscious decisions. The simplicity of access provided by a postcode-based search means that critical decisions about home improvements can be made with a robust knowledge base.

Benefit Description Impact on Homeowner
Cost Savings Identifies cost-effective upgrades Reduces long-term energy bills
Accessibility EPC information accessible from anywhere Convenient and time-efficient
Environmental Impact Encourages sustainable living Engagement in reducing carbon footprint

With energy costs on the rise, the relevance of an EPC in informing homeowners about potential energy-saving measures cannot be undervalued. It’s a win-win; not only do you get to trim down your electricity and gas bills, but you also partake in the global effort to conserve energy.

The use of a free EPC checker by postcode not only underscores financial prudence but also aligns with the broader objectives of creating sustainable homes in the UK.

Conclusively, the ability to quickly and freely check the EPC of any UK property by postcode is a significant step forward in home energy management. It’s a powerful, user-centric service that fosters greater involvement in energy-saving initiatives, potentially reducing costs and enhancing the eco-friendliness of UK homes.

Exploring Your EPC Rating Results

Unravelling the factors that culminate in your property’s energy efficiency rating is pivotal. Each component plays a critical role in your property’s EPC rating results, impacting both your environmental footprint and your fiscal outlays on energy. Here, we deconstruct the complex constellation of Energy efficiency rating factors that influence your rating, followed by a guide on interpreting EPC graphs and making sense of the EPC recommendations.

Components that Influence Your Energy Efficiency Rating

Delving into the myriad elements assessed within an Energy Performance Certificate helps to spell out why one property may score differently from another. Broadly, these factors converge to form a comprehensive gauge of a building’s energy consumption and potential for efficiency improvements:

  • Insulation Types: Be it loft, cavity wall, or floor insulation, the nature and quality of insulation have a considerable sway over heat retention and thus, energy consumption.
  • Heating Systems: From boilers to heat pumps, the efficiency of the installed heating systems directly influence the EPC rating.
  • Lighting: The presence of energy-saving LED lighting fixtures can improve the property’s rating significantly.
  • Renewable Energy Resources: Solar panels, biomass boilers or any form of renewable energy technology can catapult a property to the higher ends of the EPC scale.
  • Ventilation and Windows: The efficacy of ventilation systems and double or triple-glazing also comes into play, affecting thermal efficiency.
EPC Rating Factor Impact on Energy Efficiency Potential Improvement Measures
Insulation High impact on heat retention Upgrade to higher-grade insulation materials
Heating System Directly affects fuel consumption Install modern, energy-efficient boilers or heaters
Lighting Affects daily energy usage Replace with LED or energy-saving alternatives
Renewable Energy Reduces dependence on fossil fuels Integrate solar panels or other renewable solutions
Glazing & Ventilation Improves thermal performance Install double-glazing and efficient ventilation systems

Interpreting the EPC Graphs and Recommendations

When it’s time to decipher the EPC graphs, navigating the visual information correctly is crucial. This endeavour can transform those graphs and recommendations into actionable insights. The EPC features an ‘energy efficiency scale’, typically represented by bands ranging from A (most efficient) to G (least efficient). Here’s how to interpret some of its critical components:

  1. Current Energy Rating: Reflects the property’s existing energy performance.
  2. Potential Rating: Shows where the property can realistically aim with the recommended improvements.
  3. Top Actions: Offers a curated list of suggested enhancements that could better the property’s score.

Following are the EPC recommendations, which spell out tailored measures that could help boost the property’s rating. Suggestions may include more effective insulation, upgrading to a condensing boiler or even switching to energy-efficient lighting. Understanding these recommendations equips property owners with a plan of action towards eco-friendlier living — and, quite possibly, reduced energy bills.

Consider this: Improvement measures from EPCs are not just beneficial for the environment — they can also trim costs and add to the market value of your property.

As property owners or potential buyers, getting to grips with EPC rating results and recommendations is an exercise in environmental responsibility as well as economic savvy. With the right interpretation and implementation of energy efficiency measures, the potential for a more sustainable future becomes ever more attainable.

Navigating the EPC Certificate Lookup Process

Embarking on an EPC certificate lookup process can, at times, seem daunting. Nevertheless, with the right guidance, pinpointing your property’s energy efficiency rating via a postcode EPC search becomes a straightforward task. This section outlines common pitfalls encountered during the EPC search and practical solutions to navigate through them effectively.

Facing challenges in the EPC lookup process is not uncommon. Typically, these hurdles may include not finding your property listed or encountering outdated information. To facilitate a smoother journey, let’s consider some troubleshooting tips that will help you along the way.

  • Ensure Correct Postcode Entry: Double-check that you’ve entered your postcode accurately to prevent any retrieval issues.
  • Look for Alternative Addresses: Sometimes, the registered address may differ slightly. Consider variations or previous addresses your property might be listed under.
  • Refresh Your Search: If initial attempts fail, refreshing your search or trying at a different time can sometimes prove fruitful.

It’s important to remember that retrieving an EPC is an endeavour well worth the effort. It stands as the first step towards enhancing your property’s energy proficiency and, by extension, its market appeal and comfort level.

Issue Troubleshooting Tip
Property Not Found Recheck postcode accuracy, consider potential address variations
Outdated Certificate Information Contact the relevant authorities for an update or a new assessment
Error Messages During Search Clear browser cache/cookies, or try a different browser or device

“An EPC brings more than just compliance with regulations; it carries the potential for real energy savings and a lesser environmental impact.”

While the necessity for an accurate and timely EPC is clear, understanding the nuances of the lookup process is equally imperative. With the advice provided, you are now equipped to tackle any issues that may arise with poise and ease. Remember, a correct and current EPC not only reflects legislative adherence but also manifests commitment to energy efficiency and sustainability.

What to Do After Finding Your EPC by Postcode

After finding your EPC by postcode, embarking on the journey to improve property energy efficiency is paramount. A thorough understanding of your property’s current EPC rating can spearhead this mission. Enhancements can not only elevate your property’s EPC rating but also increase its appeal and market value. The following guidance outlines practical steps to optimise energy efficiency following an EPC assessment.

Improving Your Property’s Energy Efficiency

Capitalising on the insights gained from your EPC report, several key avenues can be explored to elevate your home’s energy performance. Prioritise measures that combine cost-effectiveness with a substantial impact on improving efficiency.

Quick Wins for Energy Efficiency

  • **Replace old light bulbs** with LED alternatives for an immediate reduction in electricity use.
  • **Seal drafts** around windows and doors to enhance thermal retention.
  • **Switch to energy-efficient appliances**, looking for those with the highest energy ratings.

Mid-Term Investments

  • **Upgrade insulation** in the loft, walls, and floors to markedly improve heat conservation.
  • **Install double or triple glazing**, particularly if your property still has single-glazed windows.

Long-Term Strategies

  • **Integrate renewable energy solutions**, such as solar panels or biomass boilers, which can transform your energy profile.
  • **Consider installing a high-efficiency boiler** or heat pump system to lower carbon emissions and fuel bills.

Each of these measures contributes to a broader strategic approach to energy management, fostering a sustained reduction in energy consumption and greenhouse gas emissions. It’s not just about the immediate benefits; it’s an investment in the future of your home and the environment.

Improvement Impact on Energy Efficiency Estimated Cost Savings
LED Lighting Moderate Up to £35 per year per bulb swapped
Draft-proofing Low to moderate Around £20 per year
Energy-efficient Appliances Moderate to high Can be significant, varies by appliance
Insulation Upgrades High Up to £250 per year (loft insulation)
High-Efficiency Glazing High Around £120 per year for a detached home
Renewable Energy Systems Very high Significant over the system’s lifetime
High-Efficiency Boiler/Heat Pump Very high Can exceed £340 per year

Contacting certified professionals for assessments and quotations is highly recommended to ensure that all improvements are executed safely and effectively. Moreover, you may qualify for government grants or incentives aimed at increasing residential energy efficiency, making some upgrades more financially accessible.

Implementing energy-efficiency improvements is a strategic approach towards a sustainable, cost-effective, and comfortable living environment. An investment in your property’s energy performance is an investment in its future.

By following through with these enhancements after finding your EPC by postcode, you take significant strides towards a greener, more cost-efficient property. The journey does not stop at the assessment; it is only the beginning of realising the full potential of your estate.

Addressing Common Misconceptions About EPC Rating Checks

Energy Performance Certificates (EPCs) can often be enveloped by a fog of misconceptions which, unfortunately, hinders many homeowners’ and potential buyers’ understanding and utilisation of this valuable resource. It’s high time we cleared the air on the common misconceptions about EPC rating checks to facilitate a more informed approach towards property energy efficiency in the UK.

One of the most prevailing EPC rating search myths is that obtaining an EPC is a complicated and time-consuming process. However, this couldn’t be further from the truth. Let us explore, bust these myths, and lay out the simple truths about EPC rating checks.

“Contrary to popular belief, an EPC rating check is neither complicated nor costly, and it provides invaluable insights into energy efficiency.”

  • Myth: EPC checks are too complex to understand.
  • Truth: EPCs offer clear and straightforward insights into property energy performance, complete with easy-to-follow recommendations for improvement.
  • Myth: You need a specialist to interpret an EPC.
  • Truth: While professional advice can be beneficial, EPCs are designed to be user-friendly with clear ratings and suggestions.
  • Myth: Getting an EPC rating is an expensive affair.
  • Truth: Many services offer free access to existing EPC ratings by postcode, and even if you need to commission a new EPC, the cost is modest in relation to the value of the insights gained.
Common Misconception Reality Check
EPCs take too long to obtain EPC assessments are quick, and the certificate is often available instantly online, or within a short timespan if a new assessment is conducted.
EPCs are only useful when selling or renting While crucial during transactions, EPCs are also a benchmark for energy improvement strategies any time.
Recommendations are too costly to implement EPCs often suggest a range of measures, from no-cost behaviours to investment in improvements with long-term savings.
EPC rating checks aren’t worth the effort EPCs can influence property value, energy bills, and carbon footprint – making them a worthwhile endeavour.

An understanding of the facts can revolutionise one’s approach to EPC rating checks. What’s often viewed as a bureaucratic necessity can in reality empower homeowners and buyers with actionable data to foster a more energy-efficient and cost-effective living space.

To truly appreciate the ease and significance of EPC checks, it’s imperative to puncture the bubble of misinformation and recognise the role these checks play in improving UK home energy use.

Correcting these misconceptions offers clarity and reassurance, confirming that EPC rating checks are accessible, beneficial, and user-friendly. It also reinforces the ambition for sustainable living, encouraging homeowners to engage more proactively with their property’s energy performance.

Up-to-Date Information: Accessing Current EPC Records

In an age where energy efficiency is synonymous with cost savings and environmental stewardship, accessing the most current EPC records is as imperative as the measures themselves. Staying informed with up-to-date EPC information ensures that you are making decisions based on the latest data, reflecting any enhancements or changes made to your property’s energy efficiency status.

To navigate the world of Energy Performance Certificates effectively, one must consider the dynamism of the database. EPCs are periodically updated to correspond with modifications in property conditions, renovations, or new installations that impact energy efficiency. Therefore, checking for the most current records is critical when assessing the energy standing of your property.

Investing time into ensuring you have the most up-to-date EPC records is a cornerstone of responsible property management and energy use.

When initiating an EPC rating search, there are crucial steps to guarantee the retrieval of current EPC records. Here’s a succinct guide to aid you in this process:

  1. Start at the official EPC Register, the authoritative source for EPC information in the UK.
  2. Input your postcode accurately to avoid any misdirected searches and ensure precision in results.
  3. Verify the date when the listed EPC was last updated to ensure freshness of information.
  4. If the records appear outdated, or if there have been significant changes to your property since the last report, consider obtaining a new EPC assessment.

These steps ensure that you are not left with stale data, thereby empowering you with actionable insights necessitated by contemporary energy benchmarks. The EPC register itself is also routinely updated, further assuring users that they are accessing the freshest reports available.

It’s worth noting that while outdated certificates might paint an unfair portrait of a property’s energy profile, recent changes in efficiency — due to upgrades or renovations — can position your property more favourably in the market. Hence, the diligence in obtaining up-to-date EPC information also has potential economic benefits.

Aspect Importance Action Required
Timeliness Reflects recent property changes Regularly check and update records
Accuracy Ensures correct information is presented Double-check entered data and certificate details
Legality Meets government EPC regulations Maintain compliance with updated EPCs
Economic Impact Affects property value and savings Use current information to inform investment decisions

If you’ve recently improved your home’s energy efficiency, be proactive in securing a new EPC — it could have a direct impact on your property’s attractiveness to buyers or renters. As environmental considerations increasingly dictate market trends, the value of current EPC records cannot be overstated. Keep abreast of your property’s status, and leverage the benefit of having an accurate, up-to-date EPC.


In summing up, the advantages of easy EPC checks are manifold and bear repeating due to their impactful nature on homeowners and renters alike across the UK. We’ve walked through the process, highlighting the simplicity and ease with which one can acquire essential data on their property’s energy efficiency. It’s evident that the straightforward nature of obtaining an EPC report fosters greater participation in environmental stewardship and can lead to tangible improvements in energy usage and cost savings.

As we’ve discussed, the EPC serves as a lodestar in the domain of property energy performance, charting a course for improvements and innovation in household energy consumption. By summarising EPC benefits, we recognise not only the immediate fiscal advantages but also the overarching contribution to a more sustainable living environment. Engaging with the details of an EPC opens the doorway to more informed decisions that reach beyond mere compliance to truly enhance the quality of our living spaces.

Encouraging energy efficiency through heightened awareness is fundamental in our collective efforts against climate change. It is hoped that the enlightening insights offered throughout this dialogue embolden UK residents to take advantage of free, accessible EPC examinations by postcode. Fostering energy awareness and performing these checks are proactive steps towards a greener UK, underscoring a shared commitment to the well-being of our planet. So why wait? The power to refine and redefine your impact on the environment is at your fingertips, as is a potentially more cost-effective home energy future.


How can I perform an EPC check by postcode?

Conducting an EPC check by postcode is quite straightforward. You can use the online EPC checking tools provided by the UK government or various other services that offer access to the EPC database. Simply enter your postcode into the search bar, and the tool will display the available Energy Performance Certificates for properties within that area.

Is there a cost involved in checking an EPC online?

No, an EPC check by postcode is usually free of charge. The UK government provides access to the EPC register, where you can search for and view EPCs at no cost to the user.

What is an Energy Performance Certificate?

An Energy Performance Certificate, or EPC, outlines the energy efficiency rating of a building. It provides a score from A (most efficient) to G (least efficient) and includes recommendations on how to improve the building’s energy efficiency. In the UK, it is a legal requirement to have an up-to-date EPC when selling or renting out a property.

Why is it important to check the EPC rating of a property?

Checking the EPC rating is essential for several reasons. It can influence your decision when buying or renting a property, as it gives an indication of the energy bills you might expect. For landlords and sellers, a good EPC rating can enhance the appeal of the property. Additionally, it is an important step in meeting legal obligations.

How can I improve my property’s EPC rating?

You can improve your property’s EPC rating by implementing the recommendations provided on the EPC. Common improvements include adding insulation, upgrading the heating system, using more efficient lighting, and installing double glazing.

What should I do if I cannot find my property’s EPC using my postcode?

If your property’s EPC doesn’t appear in a postcode EPC search, it’s possible that the certificate has expired or was never registered. You may need to contact an accredited assessor to conduct a new EPC survey. For further assistance, you can also contact the EPC register’s technical support.

Are there any common misconceptions about EPC rating checks?

Yes, one common misconception is that checking an EPC rating or obtaining an EPC is expensive and time-consuming. In reality, checking the EPC rating is free and easy, and obtaining a new EPC can be relatively quick when done through a certified assessor.

How long is an EPC valid for?

In the UK, an Energy Performance Certificate is valid for 10 years from the date of issue. However, if significant changes are made to the property that could affect its energy performance, it might be beneficial to get a new EPC sooner.

Can an EPC tell me about the carbon emissions of a property?

Yes, an EPC includes information about a property’s carbon dioxide emissions, which is a key indicator of the property’s environmental impact. It estimates the amount of carbon dioxide the property produces and includes it as part of the overall energy efficiency rating.

How up-to-date are the EPC records I can check by postcode?

The EPC records available online are kept up-to-date with the most recent assessments entered into the register. However, if a property’s EPC has expired, or if changes have been made to the property since the last assessment, the online information may not reflect the current status. Always check the date of the last certificate to ensure it is still valid.