You can't merge two customers yourself. The Streamlined team does it for you, so their invoices, payments, credits, and saved payment methods end up in the right place. If the two records are really separate locations or buyers of one business, a customer group may be all you need.
Ask the Streamlined team to merge duplicates
Email help@streamlinedpayments.com with:
the name of both customers, as they appear in Customers;
which one to keep;
whether either has a saved QuickPay card or bank account, and which should stay;
whether either is linked to Shopify or QuickBooks.
Before changing anything, the Streamlined team will check with you what moves and what stays.
Note: Until the merge is done, don't issue new invoices to the customer you're retiring.
Link related customers with a group
If the two records are different sites, departments, or buyers at the same business, keep both and put them in a group.
Select both customers in Customers.
Click Create group.
Enter a Group name.
On Scale and Enterprise, choose the Billing Account that pays for both.
A group gives you:
one combined balance and statement;
credit and payments that can move between the two;
invoices sent to one billing address.
Each customer's own history stays separate.
Who can use this feature?
Team members with Customers access, to create a group
Available on all plans. A Billing Account needs Scale or Enterprise.