1. Login to Online Check Writer and select Apps.
2. Click Xero and click Connect; then, you will be redirected to the Xero login page.
3. Sign in to your Xero account using the credentials.
4. Select the organization and click Allow access; you will get successfully connected with Xero.
5. To import bank accounts, click on Bank Account Mapping.
6. Click Import Bank Accounts and select a company.
7. Click Import.
8. Click Map Now next to the Xero bank account.
9. Select the bank account from the drop-down list and click Map Now.

To import bills from Xero, 

1. Go to Bill / To Pay from the side panel.
2. Click Import Bills and select Xero.
3. Choose the company and update Import Settings: select Time Span and Download Filter.
4. Click Start Importing.

To import invoices from Xero, 

1. Go to Invoice in the Receivables bar.
2. Click Import Invoices and select Xero.
3. Choose the company and update Import Settings: select Time Span and Download Filter.
4. Click Start Importing.