Can I Offer a Free ($0) WooCommerce Subscription?

How It Works

A subscription with a $0 recurring total doesn't need to contact a payment gateway at all for renewals, since there's nothing to charge — WooCommerce Subscriptions still tracks the subscription's status, renewal dates, and history normally, it just skips the payment-processing step each cycle. This is the standard mechanism behind free-tier or freemium subscription models.

Things Worth Planning For

No payment method is collected at signup for a purely free subscription unless you deliberately require one (some stores still collect a card up front for a smoother future upgrade, others don't bother since there's no charge to authorize).
Upgrading a free subscriber to a paid tier is handled through the switching mechanism (moving between variations, or resubscribing to a different product) — if a payment method wasn't collected at signup, the upgrade flow needs to prompt for one at that point.
Free trial vs. permanently free are different things. A free trial has an end date after which real billing starts automatically; a $0 subscription with no trial configured just stays free indefinitely unless the customer or the store changes it.
Reporting can get noisy if free subscriptions aren't filtered out of revenue-focused reports, since they're real subscription records that show up in signup/retention numbers without contributing revenue.

Setting It Up Correctly

Set the recurring price to $0 on the product, and decide deliberately whether to require a payment method at signup anyway.
Plan the upgrade path explicitly — test switching a free subscriber to a paid variation or product before launch, including whatever payment-collection step that requires.
Segment free subscriptions out of revenue reporting if they'd otherwise skew retention or revenue metrics.

See custom WooCommerce development for a freemium upgrade flow that needs more than the built-in switching mechanism provides.