Which statements need a source
Not every sentence needs a footnote. Over-citing makes pages hard to read and hides the important
sources among trivial ones. The test is simple: would a sceptical reader reasonably ask "how do you know?"
If yes, show them.
| Type of statement | Needs a source? | Example |
|---|
| Numbers and statistics | Always | "Around a third of UK households..." |
| Laws, rules and official limits | Always, to the official text or regulator | A tax
threshold, a planning rule, a consumer right |
| Health, safety and medical claims | Always, ideally to guidance or peer-reviewed research | A
recommended dose, a safe temperature |
| Findings of research | Always, to the study itself | "A trial found..." |
| Quotes and attributed opinions | Always, to where it was said | What a regulator or company announced |
| Your own tests and data | Explain your method instead | "We timed each kettle three times..." |
| Widely known facts | Usually not | London is the capital of England |
| Your professional opinion | No, but say it is your view | "In my experience, most leaks start at..." |
The last two rows matter. Citations are not a substitute for experience: when the evidence is your
own work, describe how you did it. And opinion is fine as long as it is clearly presented as opinion
rather than dressed up as fact.
Primary, secondary and circular sources
A primary source is where a fact originates: the dataset, the legislation, the study, the official
announcement. A secondary source reports on it: a news article, a blog post, an explainer. Secondary
sources are useful for finding things, but the citation should point to the primary source wherever one
exists, for three reasons.
- Accuracy. Numbers drift as they are repeated. A figure that started as "up to 30%
in one region" can become "30% nationally" three blog posts later.
- Currency. Official pages are updated when rules change; the blog that summarised them in 2022 usually is not.
- Circular citation. If you follow a chain of links and it loops back or ends at a
page with no source, the claim may never have had one. Treat it as unverified.
Good starting points for UK topics
- Statistics: the Office for National Statistics, and the devolved statistics bodies
for Scotland, Wales and Northern Ireland.
- Law: legislation.gov.uk for the text of Acts and regulations, and the relevant regulator for how they are applied.
- Government rules and rates: GOV.UK, which is updated when rates and thresholds change.
- Health: NHS pages for patient guidance and NICE for clinical guidance.
- Money: the Financial Conduct Authority for regulated products and MoneyHelper for consumer guidance.
- Research: the journal article itself, reached through its DOI, rather than a press release about it.
💡 When a news story mentions a study, search for the study's title or lead author
and read at least the abstract. Press coverage often reports the most exciting finding and drops the
limits the authors were careful to state.
How to write the citation link
The simplest and most readable citation is an inline link on the words that describe the source, placed
right next to the claim. Readers see where the fact comes from without leaving the sentence, and they
know what they will get if they click.
Weak:
Most people overpay on their energy bills
(<a href="...">source</a>).
Better:
<a href="https://www.example.gov.uk/energy-price-cap">Ofgem's
explanation of the price cap</a> shows the cap limits the unit
rate and standing charge, not the total bill.
- Name the source in the text. "According to the Office for National Statistics" tells
a reader more than a bare link, and still works if the page is printed or read aloud.
- Link the descriptive words, not "here", "source" or "this study".
- Link the exact page, not the home page of the organisation. If the fact is in a
long document, name the section or table.
- Give the date of the data when it changes over time: "in the year to March 2026" rather than "recently".
- Open in the same tab unless there is a strong reason not to. Forcing new tabs is
an accessibility irritation and does nothing for trust.
When a references list helps
For long guides, research summaries and anything health or finance related, a numbered references
section at the end lets you give full details: author or organisation, title, publisher, date and link.
Keep the inline link or a numbered marker at the claim too, because readers rarely scroll to the end
to match a claim to a source.
<section id="references">
<h2>Sources</h2>
<ol>
<li id="ref-1">Office for National Statistics,
<a href="https://www.example.gov.uk/ons-dataset">Household energy
spending, UK: financial year ending 2025</a>, published 2025.</li>
<li id="ref-2">legislation.gov.uk,
<a href="https://www.example.gov.uk/legislation">Consumer Rights
Act 2015, section 9</a>.</li>
</ol>
</section>
The fix, step by step
Step 1
Mark every claim a reader might
question
Read the page as a sceptical stranger and highlight every number, rule, research finding,
health or safety statement and quotation. Ignore common knowledge and anything clearly presented as your
own opinion. For your own tests or data, note that a method description is needed instead of a link.
On a typical long article this produces a short, manageable list, and it stops you scattering
links across sentences that never needed them.
Step 2
Trace each claim to its primary
source
For each highlighted claim, find where it first came from: the dataset, the legislation,
the official guidance or the study itself. If you only have a news article or blog, follow its links
until you reach the original, and read enough of it to confirm the claim matches what it actually says,
including any limits or dates. Where a chain of links loops or ends with nothing, treat the claim as
unverified and move it to the next step.
Step 3
Rewrite or remove what you cannot
source
Some claims will turn out to be wrong, out of date, exaggerated or impossible to trace.
Correct the ones where the original says something different, update figures to the latest official release,
soften overstatements to match what the evidence really shows, and delete anything you cannot support.
A page with fewer claims that all check out is more trustworthy than a page padded with
impressive numbers nobody can verify, and it is easier to keep accurate.
Step 4
Link the source where the claim
is made
Add each citation as an inline link next to its claim, using descriptive link text that
names the source, such as the organisation and document title, rather than words like here or source.
Point to the exact page or document, mention the section when it is long, and state the date or period
the figure covers when it changes over time. Name the source in the sentence itself so the citation
still makes sense without clicking or when printed.
Step 5
Add a references list to longer
pieces
For long guides, research round-ups and any health, legal or financial content, add a Sources
section at the end with a numbered list giving the organisation or author, the full title, the publisher
and the date for each reference. Keep the inline link at the claim as well, and give each list item an
id so numbered markers can jump to it. This gives careful readers and reviewers everything
they need to check your work in one place.
Step 6
Choose link attributes deliberately
Leave
ordinary editorial citations as normal followed links, because you are genuinely vouching for them as
the place your fact came from. Use rel="sponsored" for any link that was paid for or earns
commission, and rel="nofollow" when you must link to something you do not endorse, such
as a source you are criticising. Avoid adding nofollow to every outbound link by default, since it sends
the opposite signal about how much you trust your own sources.
Step 7
Check and repair citations on a
schedule
Run a broken link checker across your site at least every quarter and whenever you update
a page. When a source moves, find its new address; when it disappears, look for an archived copy in the
Wayback Machine or a newer official replacement, and update the claim if the facts have changed. Put
a review date on pages whose figures change yearly, such as tax rates and benefit thresholds,
so they are checked before the numbers go stale.
Followed, nofollow and sponsored: what the attributes mean
Google treats rel values on links as hints about the relationship between your page and
the page you link to. For citations, the right choice follows from why you are linking.
| Attribute | Use it for | Citation example |
|---|
| None (a normal link) | Sources you rely on and recommend | A GOV.UK rate table, a published study |
rel="sponsored" | Paid placements and affiliate links | A product link that earns commission |
rel="ugc" | Links added by users | Links in comments or forum posts |
rel="nofollow" | Links you do not want to vouch for | A misleading page you are rebutting |
Some SEO plugins and themes add nofollow to all external links automatically. Check your
settings: a site that refuses to vouch for any of its sources looks less confident, not more authoritative.
Linking out to strong sources does not "leak" anything worth worrying about.
Platform notes
WordPress
The block editor adds inline links easily. To set a rel value, several SEO plugins add sponsored and
nofollow toggles to the link box, or you can edit the block as HTML; also check whether the plugin has
a site-wide setting that adds nofollow to every external link. For references lists, a plain list block
with HTML anchors on each item works well; footnote blocks built into recent WordPress versions can also
generate numbered notes automatically.
Shopify and page builders
Rich text editors in Shopify, Wix and Squarespace allow ordinary inline links. For rel attributes
you may need to switch to the HTML view of the block. Keep a simple Sources heading and list at the end
of long blog posts.
Markdown and static sites
Inline links are easy in Markdown. Many generators support footnote syntax such as [^1],
which builds a numbered list automatically. Add a link checker to your build so broken citations fail
the build rather than going live.
Common citation mistakes
- Citing a competitor's summary rather than the official source it summarised. Readers
land on a rival's page, and you inherit any mistakes it made.
- Citing an out-of-date version. Tax thresholds, legal limits and guidance change.
A 2021 PDF is not a source for a 2026 figure.
- Linking a search results page or a paywalled article's home page, so the reader cannot actually see the evidence.
- A source that does not say what you say it does. This is worse than no source, because
anyone who checks will lose trust in everything else on the page.
- Relying on AI-generated references. AI tools can produce plausible titles, authors
and links that do not exist. Open and read every source before you cite it.
- Cherry-picking. Citing the one study that supports your point while ignoring stronger
evidence against it may look sourced, but it is not honest.
⚠️ On pages about health, money or legal rights, a wrong or stale citation can lead
a reader into a real mistake. Give these pages a named reviewer and a review date, and check every figure
against the official source each time the rules change.
Questions and answers
1. How many citations should an article have?
There is no right number. Cite every statement a sceptical reader would reasonably
question: statistics, rules and limits, research findings, health and safety claims and quotations. Common
knowledge and clearly labelled opinion do not need a source. A practical guide might need three or four
citations; a research summary might need twenty. Adding links to sentences that do not need them makes
the important sources harder to find and the page harder to read, so aim for coverage of real claims,
not a quota.
2. Do outbound links to sources help or hurt SEO?
Linking to relevant, reliable sources does not harm your rankings, and it helps readers
check what you say, which supports the trust side of E-E-A-T. Google has not said that outbound links
are a direct ranking factor, so do not add them for that reason alone. The worry that linking out leaks
value is not worth acting on for genuine citations. What does cause problems is linking to spammy or
irrelevant pages, or selling links without marking them as sponsored.
3. Should citation links be nofollow?
Usually not. A normal followed link says you rely on this page as a source, which is
exactly what a citation means. Use rel sponsored for affiliate or paid links, rel ugc for links added
by users, and rel nofollow only for pages you link to but do not want to vouch for, such as a misleading
article you are rebutting. Some plugins add nofollow to every external link by default; switch that off
for editorial citations.
4. Is it all right to cite Wikipedia?
Wikipedia is a good place to start research, not usually the best place to cite. Its
articles change, and they are themselves summaries of other sources. Scroll to the references at the
bottom of the Wikipedia article, follow the one that supports your point, read it, and cite that original
source instead. For uncontroversial background facts a Wikipedia link does little harm, but for statistics,
legal points or health claims, cite the primary source directly.
5. What should I do when a source I cited disappears?
First look for the page at a new address on the same site, since organisations often
reorganise their websites. If it has gone, check whether a newer official version exists and whether
its figures differ; if so, update your claim. If the claim is historical and still accurate, you can
link to an archived copy in the Internet Archive's Wayback Machine and say it is archived. If nothing
supports the claim any more, rewrite or remove it.
6. Can I cite my own previous articles as sources?
You can link to your own articles for further reading or to explain a point in more
depth, and that is useful internal linking. But your own article is not evidence for a factual claim
unless it contains original data or research with its method explained. If your older article made a
claim based on an external source, cite that external source directly in the new piece. Circular citations
that only lead back to your own site do not help a reader verify anything.
7. How should I cite a statistic that changes every year?
Name the source and the period the figure covers in the sentence, for example the Office
for National Statistics figure for the year to March 2026, and link to the specific release. Where possible,
link to the landing page for the series rather than a single PDF, so readers can find the latest version.
Then set a review date on the page for when the next release is due, and update the figure and wording
when it comes out.
Find the unsourced claims on your pages
The E-E-A-T Checker scans your page for citation patterns, along with bylines, bio depth, Person
markup, update dates, trust pages and reviewer disclosures, and links each finding to the guide that
fixes it.
Open E-E-A-T Fixes →