How do I import all transactions from. my old device to the new device

Hi there and welcome to the QuickBooks Community!

Using QuickBooks Self-Employed to track the income and expenses for your small business is a great choice. When you get a new mobile device it's important that you're able to reload and maintain access to the apps and programs that you love. Let me help you out with this.

When you use QuickBooks Self-Employed, the data you enter such as your transactions, isn't restricted to one device, but can be accessed using any device or web browser and your sign-in credentials. When you get a new device, you'll simply need to download the QuickBooks Self-Employed app and log in using the same username and password that you used previously. All of your transactions will be there waiting for you.

If you mean that you've created a new subscription and want to be able to import your transactions from an old account to your new one, that's not quite so straightforward. You have the ability to Manually import transactions into QuickBooks Self-Employed which is a way to bring the transactions that you download from your bank as a .CSV file into QuickBooks. You'll have to categorize them again in order for them to have the same detail that they did in your previous subscription. Other account data will have to be re-entered such as Invoices. 

Let me know if I can be of further assistance. It's what I'm here for.