To add GST to invoices you create in your Tide app, you’ll need to add your GST number to your profile. Here’s what to do:

1. Open your Tide app and go to ‘Invoice’. 
2. Tap on ‘Manage’ at the top, and then on ‘Template’. 
3. Go to the ‘GSTIN’ field and add your GST number.

Now, you’ll be able to choose the GST rate for each invoice you create. The invoice PDF generated will have your GST number.