How do I get tags on invoice items to carry over to the payment account?
Found at:
The simple answer to the original poster's wish is: You can't. Quicken will not automatically apply the tag assigned to an invoice item, to the payment used to pay that invoice item.
I'm not convinced that the op's desired use for having the Tag assigned to the invoice payment is worth the effort to do it, but: I believe there are a number of approaches to accomplish the op's desired result.
At the end of the day, I think the simplest approach is as follows.
When an invoice payment is received from the Customer/Tenant, enter it first as a New Customer Payment in the appropriate Quicken invoice account.
The resulting PMT transaction will have category that is a "transfer" to the desired (real-world) deposit account (typically a checking account).
At that point, the PMT transaction in the invoice account can be modified: in its Category field, the transfer category can have a Tag suffixed. Example (assuming the actual payment was deposited in a Quicken account named "Rental Checking"): modify the invoice account PMT transaction category to "[Rental Checking]/Property-tag" (no quotes). That newly assigned Tag will be carried over to the payment transaction in the deposit account (to the transaction in the checking account).
After that, any downloaded payment transaction for that invoice can be Accepted as a Match transaction in the payment deposit account.
[I believe the op misunderstood the instructions he states he found. The op was trying to modify (append the Tag to the Category of) the payment transaction in the deposit (the "checking") account: that does not work - or more accurately, that will cause extra work for the user to get the desired result.]