Can I use the Home Buyers' Plan a second time if I've already paid back my first withdrawal?

Generally, yes. Using the Home Buyers' Plan once doesn't permanently disqualify you from using it again later, provided you fully repaid your earlier withdrawal and you otherwise re-qualify as a first-time buyer under the plan's rules at the time of your new withdrawal. It isn't a strict one-time-only lifetime bar, but it also isn't automatic just because your first withdrawal is paid off.

The part that trips people up is the eligibility test itself: the Home Buyers' Plan's "first-time buyer" requirement depends on your ownership history over a defined period before the new withdrawal, not simply on whether you've used the program before. So even with a fully repaid first withdrawal, you need to independently meet the ownership-history conditions again at the time of your second withdrawal - owning or having recently owned a home in the relevant window can disqualify a second use, even though a past HBP withdrawal on its own does not. Before assuming a second Home Buyers' Plan withdrawal is available to you, it's worth confirming that you currently meet the eligibility conditions as they stand today, since re-qualifying is the real gatekeeper here.