My last accounting system used accrual accounting, but it appears that QuickBooks Self-Employed uses cash-based. It doesn't really matter to me which I use, whichever is easiest to track (in this case, cash-based now). However, I have an invoice that is dated 2018 that was paid in 2019. QBSE is estimating my 2019 taxes including that payment, but I already paid taxes on it last year. How do I account for this? Also, how do I link invoices to their payments in QBSE?