Paycheck parking works because your line of credit can absorb your income and your spending as they flow through the month. But there's a rule that has to sit on top of it, or the whole thing gets fragile. Never run the line to its limit. Always keep a cushion of open credit sitting there unused.
Here's why. The strategy only helps if the line stays available. The day you max it out, you've turned a flexible tool into just another maxed card, and a real emergency, the transmission, the medical bill, the gap between jobs, has nowhere to land. Worse, some lines can be frozen or reduced by the lender when they see you riding the limit, which is exactly when you'd want the room most.
How much cushion? A common-sense floor is a few thousand dollars or a month of expenses kept open at all times, whichever is larger for your household. That's money you don't touch for parking or chunking. It's the same reason you keep a regular emergency fund even while you run this. The line is a cash-flow tool, not your safety net, and asking it to be both is how people get hurt.
A variable line can also reprice against you. If rates jump and your balance is near the ceiling, the payment can climb faster than you planned. Leaving room isn't just about emergencies, it's about surviving a rate you didn't see coming without breaking a sweat.
The full method, with the cushion built in, is on the How It Works page. And once your cash flow is humming and a surplus starts piling up, the question of where that pool should live is over at Lifetime LOC.