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8 things to check before your SMS API integration goes live

8 things to check before your SMS API integration goes live

8 things to check before your SMS API integration goes live

SMS API checklist

8 things to check before your SMS API integration goes live

Below you’ll find some of the most commonly overlooked things that have caused SMS integrations to go wrong almost immediately.

Before you press ‘go’ on your SMS API integration, have a quick look at these 8, easily made mistakes. 

It could save you a whole world of grief.

1. Check your messages are using the GSM character set

Our SMS API platform uses the GSM character set for transmitting SMS.

GSM CharactersetIf a message contains any character outside the GSM alphabet, UTF-16 encoding will apply, along with a 70-character limit on message length

This allows us to support the sending of emoticons, which many customers need.

UTF-16 encoding a message dramatically reduces the numbers of characters available per text credit. Instead of the usual 160 characters, a UTF-16 encoded message allows just 70.

This is reflected in the number of credits used to send the message (i.e. we will charge you 1 credit per 70 characters.)



Don’t be tempted to copy and paste content from Microsoft Word or other word processing applications. This would probably result in non-GSM characters being used and the message sent as UTF-16. 

Some characters, such as certain apostrophes and hyphens may appear to be in the GSM character set but actually contain subtle differences.

The apostrophe and hyphen are probably the most commonly mis-used characters.

2. Triple-check your code in all possible scenarios

Please make sure that you’ve thoroughly checked your code so that it functions as expected in all different scenarios.

Make sure that you’ve understood the error codes that we respond with and that your system responds appropriately.

Check that your code can’t run wild and send out messages in an uncontrolled way.
You don’t want to find that your SMS credits have all been consumed very quickly because of an obvious error.

I’m afraid we can’t refund credits that have been lost in this way. Our code samples have been thoroughly tested but it’s important that you ensure they work in your unique set-up.

(Again, we can’t be held responsible for problems that arise because of use of our code snippets in your environment.)

We have a flooding filter which is there to help prevent a single person receiving multiple messages in a short space of time.
A single number can only receive 20 varied messages and 3 identical messages per hour.

In some situations though, the flooding filter may not prevent multiple message being sent, so please don’t rely on it to prevent multiple messages being attempted. (We can’t refund credits that have been lost because the flooding filter didn’t stop messages being delivered.)

Please also check that the flooding filter won't prevent intended messages from being delivered.
If you're using our service for server alerts for example, it's conceivable that you maty want to send more than 3 identical messages in a 1 hour period.

3. Set up low credits warning email alerts

Running out of SMS credits is a worry for most customers. To prevent this happening, you can set up low credits warning emails.

You’ll be sent daily emails when your account falls below a set number of credits remaining.

To set up your low credits warning alerts, simply log into your account and scroll to Low Credit Warning. Here you can set the number of credits below which the alerts will be triggered.

Low SMS credits warning

We suggest that you trigger the alerts when you have about 3 weeks of credit remaining. That way you’ll have plenty of time before the account runs out.

Don’t forget to add all the contacts that need to receive the alerts.

You can also apply for an SMS overdraft. This allows your account to continue sending even if the credit level falls below zero. 
This overdraft is agreed with us in advance and we usually set the overdraft to around 2 weeks of SMS usage.

4. Check you have the relevant permissions to send SMS

Since GDPR came into force in May 2018, the rules surrounding the sending of marketing texts have become stricter.

If you’re planning to send marketing texts to your customers,  you’ll need to make sure you have their permission.

Failure to do so could result in some rather alarming fines if people complain.

The rules are designed to protect consumers but there’s nothing too much to worry about. There are a number of ‘legitimate interests’ that allow you to send marketing texts.

5. Make sure that replies are being handled correctly

If your SMS service has a reply option, ensure that your have configured the URL to which you want incoming texts to be sent and that it’s been tested from end to end.

Incoming texts can also be sent to you by email. This can be easily configured in your account.

6. Check the message length is as intended

A standard text message using the GSM character set is 160 characters including spaces. Messages that are longer than 160 characters will use more than one text credit. Messages can be up to a maximum of 1280 characters in length.

Messages longer than 160 characters get segmented into chunks of 153 characters to send to the recipient's handset, so you'll be charged 1 credit per 153 characters.

(The missing 7 characters are used to insert instructions to stitch longer messages together, so that they arrive as one long text rather than a series of texts.)

For more information on the credit usage, please visit our developers' page.

Before your SMS integration goes into production, please make sure that you've checked that message length is correct. Unfortunately, we can't refund credits that have been consumed because of a miscalculation.


7. Failed international texts are not refunded

This is more of a reminder than something to check. Non-delivered international texts are not refunded back to customers’ accounts.

The reason for this simple. We are charged for all non-UK SMS traffic that we submit, so we have to charge for international texts, regardless of delivery outcome.

Also, please note that if you're intending to send messages outside the UK, then you will need to contact us so that we can enable your account for international sending. Don't worry though, it only takes a minute.

International delivery reports are also far less detailed than those for the UK. In many cases we are unable to determine why a particular message has failed as the relevant network do not always provide us with the relevant information.

Unfortunately when this is the case we won't be able to obtain further information.

If you're planning to send messages outside the UK, please  also read this important article about international SMS. It highlights a few things you need to be aware of.

One final note. It costs more to send to international mobile numbers. Here's a link to our international pricing table.

8. White list our domains

If you’re using our SMS to email reply function, make sure that our emails aren’t going to get stuck in your spam filters.

If you ever change your login credentials, you’ll also need to be able to receive emails from us.

The 2 domains from which email are sent are as follows.

Please contact us if you need to white list our IP address, so that you can receive data sent to a URL endpoint. ([email protected])

Can we help at all?

If you run into any bumps in the road while getting your SMS integration ready for action, then please don’t hesitate to be in touch. We may be able to help.

Sometimes, just having a different set of eyes on a problem can help a solution emerge.

Customers have said some very kind things about our service, reliability and support, so I hope we’ll be able to provide you with a top notch service.

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