Articles on: Square Integration

Invoice part payments using the Square terminal

The Square terminal can be used to take a part payment for an invoice. This might be useful in situations where you have an invoice which is to be partially paid by a third party like an insurance company, with the client responsible for an excess payment. An invoice part payment via the Square terminal will incur a charge of 1.75% per transaction.

Site administrators and privileged users are the only users who can access saved invoices, and therefore are the only users who can take a part payment for an invoice via terminal.

To take a part payment for an invoice using the terminal:

Create and save the invoice containing the appointment(s) and expense(s) you'd like to take payment for, or open an existing invoice

Create the part payments which will apply to the invoice

You can then initiate the card part payment in one of two ways:

i) On the part payments screen, click on the three dots at the end of the row containing the payment you'd like to take and choose Pay with Terminal:


ii) From the invoice itself, click on the Square icon at the bottom right, then chose which payment you'd like to take:

Check that the amount being displayed matches the added part payment:

Click on Take Payment

If you have one terminal linked to your WriteUpp account, clicking on Take Payment will start the payment and sent the total amount payable to the terminal.

If you have multiple terminals linked, you'll be asked to select which one to send the payment to. Clicking on Confirm will then start the payment and send the requested amount to the terminal:

While the payment is being sent, you'll see Sending payment displayed on screen:

Once the connection has been made, you'll see Waiting for terminal

This process should only take a few seconds. If you find yourself stuck on this screen for a while, check that terminal is on, connected to a network and that there isn't another payment being processed

Terminal will confirm that it is ready for payment to be made. At this point you can confirm the amount displayed on screen matches that on terminal and present the terminal to your client for payment:

The client will insert, tap or swipe their card, and the terminal will process the payment. Once the payment has been made, the terminal will show that it has been approved and provide you with an option to generate a receipt. If the payment fails for any reason, you'll see the reason displayed on terminal and can tap on OK at the bottom of the terminal screen to allow your client to try again.

The terminal will send WriteUpp a message to confirm that the payment is complete. Clicking on Refresh the page will take you to either the part payments page or the invoice, depending on where you initiated the payment:

If the payment is cancelled, either from WriteUpp or on the terminal, you'll also receive a message to show this in WriteUpp:

The part payment will be marked as paid, and the invoice as a whole will be marked as part paid (or paid, if the terminal payment covered the remaining balance):

The payment will appear in your Square dashboard under transactions, identified by the WriteUpp invoice number:

The further information on the transaction in the Square dashboard, and on the receipt that can be printed from terminal, will show the payment as being for a ​"Custom amount":

Unfortunately we are not able to pass the name of the item to terminal to be displayed in place of "custom amount" at this time and there is no way to change how this appears.

As pictured above, if you use the terminal to take multiple part payments for the same invoice, you'll see each transaction listed separately in Square but with the same invoice number.

Invoice part payments via the Square Terminal will incur a transaction fee of 1.75% per transaction

Square is only available to WriteUpp users based in the UK. For those of you who are not UK based, you will be able to set up Stripe, which allows online payments only

Updated on: 07/09/2023

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