Bill earlier in the work, not only at the end
Deposits and milestone invoices convert verbal enthusiasm into scheduled cash. A 30–50% start deposit is normal for project work; progress bills keep both sides honest about scope.
State late fees and pause-of-work clauses politely in the contract before you need them.
Match send timing to client AP cycles
Many firms run payment batches on fixed days. Ask when AP processes invoices and submit at least a few days earlier with complete PO numbers and coding.
Electronic invoices with clear line items beat PDFs buried in long email threads.
Build a personal cash buffer anyway
Even perfect invoicing leaves gaps. A one-month operating buffer turns slow payers into annoyances instead of crises.
Track average days-to-pay by client and fire or reprice the chronic late cohort.