In Washington, your final paycheck is due on or before the next scheduled payday, whether you quit or were fired.
Final paycheck deadline in Washington
What your final pay must include
Your final paycheck must include all the wages you earned through your last day. Whether it also has to include unused vacation depends on your state and your employer's policy, some states treat accrued vacation as wages that must be paid out. See Washington PTO payout rules. If an employer misses the deadline, many states add penalties. This is general information, not legal advice.