Style and grammar

Punctuation, capitalisation, and formatting for UX components.

These rules are most relevant for UX writing. For more in-depth guidance, read OVO’s full Copy Guidelines.

Use the active voice

Make sure the subject of your line performs the action.

  • Active: “We’ve cancelled your transaction.”
  • Passive: “Your transaction was cancelled.”

Ampersands (&)

We use 'and', not '&' or any other symbol. This is important for accessibility and professionalism.

The exceptions:

  • in push notifications, social and SMS, if the word count is tight - but make sure to stick to '&' throughout the same copy for consistency
  • if it's part of a recognised brand name, or a comonly used word like B&B, after writing out 'bed and breakfast' first
  • M&S
  • B&B
  • R&D

Check your energy use & payments

Bullet points

Bullet points simplify everything. They’re great at structuring lengthy or complicated text, breaking it down so it’s easier to understand.

Because of this, bullet points by nature should be short and punchy.

The exception is long blog content when we sometimes use longer bullet points to break up big chunks of text.

  • have a lead-in line to introuduce the bullet points
  • hyperlink relevant text in the bullet point, if adding a link

End simple sentence bullet points with a full stop. The exception is any single bullet point that has more than one sentence. If this is the case, you then need to add full stops to all bullet points in that set.


Choose OVO for your energy and you get:

  • 100% renewable electricity
  • 1 carbon-busting tree planted every year
  • service rated “excellent” on Trustpilot
  • You’ll be getting 100% renewable electricity as standard.
  • We’ll plant a tree in your name every year.
  • Get service rated “excellent” on Trustpilot.


Capitals can slow users down when reading online. This means we only capitalise the first word in a sentence, unless the word is a proper noun (a name - for example of a product).

Common OVO examples:

  • Better Smart energy plan
  • Charge Anytime
  • Energy Experts
  • energy tracking
  • Greener Energy
  • home services
  • OVO Beyond
  • Path to Zero
  • Planting Promise
  • Power Move
  • smart meters
  • solar


Use the oxford comma. For example: All our plans come with unlimited call-outs, access to Gas Safe engineers, and more.

Consistent language

When referencing common OVO topics, be sure to align your words with the rest of the brand. Check the brand lexicon.


When asking users to input dates, keep it simple: dd/mm/yyyy

We abbreviate months and days in UX copy, text messages, and social media posts where space is limited. We use:

  • Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
  • Mon, Tue, Wed, Thur, Fri, Sat, Sun

Where we have more space (like a landing page on our website) we should spell the month and date out in full, for example: 'We’re launching on 31 September 2023'.

When dates are together in a list, such as in billing or usage contexts, abbreviate the month. For example:

  • 31 Dec 2022
  • 1 Jan 2023

Use ‘to’ between dates to indicate a range as it's better than a hyphen or dash, for accessibility. For example: 1 Jan 2023 to 1 Apr 2023.

First and second person

Use indefinite articles ('a', 'an') and pronouns ('you', 'your') sparingly, especially for functional account actions like paying bills.

Double check whether indefinite articles are really necessary in the meaning of your copy. Shorter is always preferable. See for example: Pay bill vs Pay a bill.


We mostly use the metric system:

  • metres
  • centimetres
  • millilitres
  • kilos
  • grammes
  • metric tonnes (1,000kg)


  • 0 to 9mm
  • 1 to 99cm
  • 1 to 1600m
  • miles for more than 1,600m


  • 0 to 999ml
  • 1l to 999l
  • 1m³ upwards


  • metres per second
  • miles per hour


  • 0 to 999g
  • 1kg to 999kg
  • 1 tonne, 2 tonnes upwards


  • 1 to 99cm²
  • 1m² to 999,999m²
  • 1km² upwards


Degrees celsius written as 23C with a capital C and no degree symbol.


Keep kWh to:

  • 2 decimal places if under 0, and include 0 - for example: 0.38
  • 2 decimal places if under 10 - for example: 9.25
  • 1 decimal place if 10 to 99 - for example: 30.3
  • 0 decimal places if over 100 - for example: 213
  • omit decimals if possible - for example: 9 rather than 9.0


Use the £ pound symbol before the amount

In UX contexts, always include the full amount, including pence. Add in 2 decimal places, even when the amount is a whole number. For example:

  • £20.00
  • £4.99

In marketing contexts, add in 2 decimal places unless the amount is a whole number - for example: £20.

Web addresses

Web addresses can be hyperlinked

When we write web addresses, omit 'www.'

Use like this:

Go to

Visit our website,

Not like this:

Go to

Visit our website

Phone numbers

  • Omit brackets around phone numbers
  • For mobile numbers, add a space after the fifth digit
  • When writing from the UK to UK audiences, omit the +44
  • For international audiences, drop the zero and use +44 XX XXXX XXXX
  • For British and international audiences, use +44 (0)XX XXXX XXXX


We use am and pm, without a space after the number. For example:

  • 7am
  • 7pm

Use a colon for minutes, for example:

  • 7:30pm
  • 7:45pm

Don’t use 12pm or 12am – use midday or midnight.

When referring to 2 different times use 'to' inbetween as it's better for accessibility. For example:

  • 8am to 9am
  • 8am to 9:30am
  • 8am to midday
  • 8am to 4:30pm