Top tips for creating an effective subject line

5 minute read

Picture the scene: you’ve created your email, you’re ready to send and then at the last minute you realise you haven’t thought of a subject line. Never mind, you quickly add one and off the email goes. However, how much thought went into it? The subject line has a big part to play in a recipient’s decision to open or delete your email and as such we thought we’d list our top tips for creating an effective line, which can help boost those all important open rates.

Initial pointers

  • Avoid using exclamation marks and percentages.
  • Be careful with the use of ‘hot words’ such as ‘free’ or ‘money off’ as they can sometimes be picked up by email providers as spam.
  • Avoid having lengthy subject lines. You’re more likely to get a reaction from short, snappy ones. Try and keep them no longer than 60 characters.

Call to action

Give people a reason to open your email! If you’re advertising a special offer or making an announcement, tell them. Perhaps you have an offer on that’s ending shortly? Stressing urgency in your subject line can help get the reaction you want.

Example subject lines:

  • 24 hours left to take advantage of our special offer
  • Our latest in store offer is available to download now

You’ll be more likely to get a reaction from subscribers if they feel there’s information in your email that they don’t want to miss. However, make sure your subject line is honest – try not to claim your email includes something it doesn’t as that’ll lead to unsubscriptions.


Where possible try and make your subject line conversational and friendly. The art of permission marketing is about developing a relationship with customers and your subject line should reach people on a personal level. Furthermore if there’s something going on, like it’s a hot sunny day or it’s the festive period, mention it. People can relate to this so will be less likely to dismiss your email, just try and ensure it remains relevant to your business.

Example subject lines:

  • It may be raining outside, but come and see our new store soon
  • Celebrate the summer sun with our new menu


To make your subject line relate to subscribers it’s a great idea to personalise it. This can be done in several ways, for example perhaps you have a list of customers who have recently purchased a ticket to an event you’re holding. Or perhaps you’re a retailer and you want to send an email to everyone who has visited a specific store. Why not mention the store in the subject line? If it’s something familiar to them they may be more likely to open your email, and a little bit of tailoring on your part can really make all the difference.

Example subject lines:

  • Thanks for buying a ticket – full line up now announced
  • New clothing line in our London store

Split testing

In order to fully understand how effective your subject lines are we recommend using split testing. Split testing enables you to find out what resonates with your readers so it’s great for understanding how subscribers are likely to interact with you. It allows you to constantly improve your results and increase your ROI. In your account you can test up to five campaigns in one send so why not give it a go and see what results you get? We use split testing ourselves and often find a big difference by including our company name in the subject line.

Below are some examples for a typical campaign that you could use – but don’t forget split testing can be applied to any element of your email, not just the subject line!

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We hope this has given you a useful insight into how to create an effective subject line. Do you have any recommendations? Feel free to share them with us in the comments box below!