Skip to content
Postworks Portal
  • There are no suggestions because the search field is empty.

How to set up and send SMS messages

This article explains how to set up an SMS Postbox, format your data and send text messages through your Postworks account.

 How to set up and send SMS messages

This article explains how to set up an SMS Postbox, upload recipient data, preview messages, submit an SMS send and track your messages in Postworks.


Before you start

You need an active Sender ID to send text messages. A Sender ID is a short word, such as your company name, that identifies you as the sender. It acts as the display name recipients see on their mobile phones.

  • Account admins must request a Sender ID through our support team.
  • Our support team will also need to activate SMS on your plan.
  • Once activated on your plan, account admins must turn on SMS access for individual users on the Users page.

Your Sender ID must follow these rules:

  • Be between 1 and 11 characters long, although we recommend at least 3.
  • Contain at least one letter.
  • Use only letters (a–z, A–Z), numbers (0–9) and hyphens.
  • Do not include spaces, and do not start or end with a hyphen.


How to set up an SMS Postbox

  1. Select Send from the main menu.
  2. Select Create new.
  3. Enter a Postbox name.
  4. Select Type, then choose SMS.
  5. Select Choose Example Data File and upload an XML, CSV or XLSX file containing your recipient data.
  6. Select Phone number column and choose the column header from your file that contains your phone numbers.
  7. Enter your message in SMS template. You can include placeholders from your data file to personalise each text.
  8. Select From Display Name and choose your approved Sender ID.
  9. Select Create.


How to send an SMS batch

  1. Select Send from the main menu, then drag and drop or browse to upload your data file to your SMS Postbox.
  2. Review the Phone number validation screen. Your recipient numbers are sorted into three tabs:
    1. ACCEPTED: Valid phone numbers with supported country codes.
    2. INVALID: Phone numbers that are incorrectly formatted or too long. These rows are excluded from the submission. Select Download Excel if you want to download a record of invalid entries.
    3. FORBIDDEN: Valid phone numbers for countries that are not currently on our supported whitelist.
  3. Select Continue.
  4. Review the preview screen showing the first 5 items in your submission. Check the text content and the Message parts count on each item.
  5. (Optional) Select Send test SMS to receive a sample message.
    1. Choose whether to send the test to the mobile number saved on your My details page or enter a different mobile number.
    2. Select Confirm. Test messages incur a charge per part on live accounts.
  6. Select Continue to open the Submission summary.
    1. Review the total text message count, accepted phone numbers count and total cost (excluding VAT). Failed messages are listed separately and are not charged.
  7. Select Confirm.
  8. On the Ready to send? prompt, select Yes. SMS submissions cannot be recalled or cancelled after submitting.

 

How to view and track your text messages

You can check the status of your sent messages and view previews at any time.

  1. Select My post from the main menu, then choose Text messages.
  2. Filter your messages by selecting the dropdown under Text Message Status. You can filter by:
    • Created
    • Sending In Progress
    • Sent
    • Failed
  3. Check why a message failed by hovering over the information icon next to a Failed status. A pop-up box will display the specific reason.
  4. Preview an individual text message by selecting the green icon in the Action column next to the item. This opens the View item screen, showing the full message preview, recipient phone number, sender details, item URN and message parts count.

SMS status list2

Formatting your phone numbers

To prevent failed sends, always include country codes in your phone numbers. When we validate your data, our system automatically cleans phone numbers by removing spaces, dashes and brackets.

Any phone numbers without a country code, or starting with a zero (01 to 09), automatically default to UK formatting.

  • Correct formatting: +44 7123456789, 0044123456789 or (44)123456789.
  • Incorrect formatting: +0044123456789 or +(02)123456789.


Message limits and charges

You are charged for each part of an SMS message. Pricing varies by country.

  • Standard characters: A single text using standard characters is up to 160 characters. Messages longer than 160 characters split into parts of 153 characters.
  • Extended characters: The following nine symbols count as two characters each: |, ^, {, }, €, [, ~, ], \.
  • Special characters: Characters outside the standard character set (such as non-Latin alphabets or curly quotation marks) change the single message limit to 70 characters. Longer messages split into parts of 67 characters.
  • Placeholders: Allow an average of 7 characters per placeholder when estimating message length.
  • Maximum length: Each recipient can receive a maximum of 10 message parts per submission.

Standard GSM charactor set

The maximum number of items you can include in a single submission depends on your plan:

  • Starter: 10,000
  • Professional: 50,000
  • Enterprise: 100,000
  • Custom: 50,000


Supported countries

We currently support sending text messages to the following countries:

  • United Kingdom (+44)
  • Bahrain (+973)
  • Denmark (+45)
  • France (+33)
  • Germany (+49)
  • Ghana (+233)
  • Greece (+30)
  • Iraq (+964)
  • Ireland (+353)
  • Italy (+39)
  • Nigeria (+234)
  • Norway (+47)
  • Qatar (+974)
  • Saudi Arabia (+966)
  • Spain (+34)
  • Switzerland (+41)
  • Turkey (+90)
  • United Arab Emirates (+971)


Troubleshooting

You see a red error banner saying "Merged text exceeds the maximum allowed parts"

Your template text combined with placeholder data has exceeded the 10-part limit (over 1,530 standard characters or 630 special characters). Shorten your template or reduce the size of your placeholder data before trying again.

You see numbers listed as Forbidden during validation

This means the destination country is not on our supported list. Contact our support team to request adding the country.

Your message is split into more parts than expected

Check your template for extended or special characters, including curly quotation marks. These reduce character limits and increase send costs.


Need more help?

If you’re still having trouble, contact our support team via email or live chat and we’ll help you take a closer look.