The Uncomfortable Part
The integration can be working perfectly and your books can still be wrong
This is the single most useful thing to understand about ServiceTitan and QuickBooks, and it is the thing nobody says out loud during a demo. A green export status means the records were accepted by QuickBooks. It does not mean they were accepted into the right accounts, in the right period, at the right amount.
Consider the merchant fee. ServiceTitan does exactly what it should: it records a $10,000 invoice and a $10,000 payment. The processor takes $300 and deposits $9,700. Both systems are internally consistent. The bank statement is internally consistent. And your QuickBooks bank account will never reconcile, because $300 of real money left the building and nothing in the pipeline told the ledger about it. Multiply that by a year of card volume at a shop doing $8M and you are looking at a six-figure reconciling difference that someone eventually plugs to an "Ask My Accountant" account and stops thinking about.
Or consider timing. The card processor auto-batches overnight and the payment exports to QuickBooks. The invoice it belongs to has not been posted yet, so it exports the next day. For those twenty-four hours QuickBooks has a payment with no invoice to apply against, which shows up on the balance sheet as negative accounts receivable. Do that every day for a year and you have a permanently distorted A/R aging that no amount of re-syncing will clean up.
None of this is caught by the integration, because none of it is an integration failure. It is an accounting configuration failure, and it needs an accountant who has seen a ServiceTitan file before. That is precisely what our ServiceTitan bookkeeping services exist for. The specific mapping fixes are laid out on the QuickBooks and ServiceTitan integration page, and everything else we have written for ServiceTitan shops is on the ServiceTitan hub.