Switching from Substack to Kit: what happens to your fees

Under 10,000 subscribers, it is a straight fee cut

Start with the case most Substack writers are actually in. Kit's free Newsletter plan covers up to 10,000 subscribers and — unusually for a free tier — it can sell paid subscriptions, so a list inside that ceiling pays Kit no plan fee at all. Take 5,000 subscribers with 250 paying $10/month — $2,500/month gross. On Substack that costs $415/month all-in (16.6% of gross). On Kit it costs $162.50/month (6.5%), every cent of it the commerce fee. That is $252.50/month — about $3,030/year — for the same revenue, with no fixed cost taken on in exchange.

Because there is no plan fee to cover, there is no paid count at which Substack comes out cheaper inside the free tier: at $10/month, Kit's $0.65 per paid subscriber beats Substack's $1.66 from the first sale, on a list of any size up to 10,000. The full side-by-side is in Kit vs Substack, and what Kit's free plan does and doesn't include is in Kit pricing explained.

Above it, Kit charges a plan fee — and still usually wins

Past 10,000 subscribers Kit moves you onto a paid plan, and the comparison becomes the familiar one: a flat fee against a percentage. Take 25,000 subscribers with 1,000 paying $10/month — $10,000/month gross. On Substack that costs $1,660/month all-in (16.6% of gross). On Kit's Creator plan it costs $815.83/month (8.16%): $165.83 of plan fee and $650 of commerce fee. That's $844.17/month — about $10,130/year — for the same revenue.

The reason is structural. Substack's 10% scales with revenue — the more you earn, the more it takes — and on top of it you pay Stripe's card fee (2.9% + $0.30 per transaction) and its 0.7% recurring-billing fee, which is why the all-in rate lands near 16.6% rather than a clean 10%. Kit's commerce fee is only 3.5% + $0.30 — and that fee includes payment processing, so there's no separate Stripe charge stacked on top. The trade is a fixed plan fee that scales with your list size, not your revenue. Push the same math to 50,000 subscribers with 2,000 paid at $10/month ($20,000/month gross) and the gap widens: $3,320/month on Substack versus $1,615.83/month on Kit's Creator plan — $1,704.17/month, or about $20,450/year. The mechanics behind this trade-off are spelled out in flat fee or revenue share.

When staying on Substack is the right call

Above the free tier the savings run in reverse at a small paid base, because Kit's plan fee is a fixed cost you pay no matter how little you earn. On a 25,000-subscriber list at $10/month, the crossover sits around 165 paid subscribers — roughly $1,650/month gross, or 0.66% of the list paying. Below that, Substack's pay-as-you-earn 10% is the cheaper home and migrating would cost you money; above it, Kit pulls ahead. The bar falls as the list grows, because Kit's brackets climb far more slowly than a list does — what conversion rate you need before leaving Substack saves money walks it across every size. If you're near that line, run your real numbers in the calculator before moving.

The free tier changes what "small" means for this particular move. On most flat-fee platforms a small paid newsletter is exactly the one that should stay on Substack; on Kit it is the one with the cleanest case for leaving, because there is no plan fee to spread until the list passes 10,000 subscribers. The awkward zone is just above that ceiling with few paying readers — a plan fee newly switched on over a thin paid base. How many paid subscribers it takes to cover your platform bill puts a number on that hole.

What to verify before you move

A few things to confirm directly with both platforms before committing, since they affect real money: that your paid subscriptions can transfer through Stripe without forcing subscribers to re-enter cards — Substack bills through its own Stripe connection and Kit through Kit Commerce, so ask specifically; how annual subscribers are handled mid-term; and Kit's current import process for your subscriber list, tags, and automations. Migration mechanics change often enough that we keep them out of our data layer — verify against Kit's site and Substack's docs at migration time.

And weigh what isn't a fee. Substack's network — recommendations, the app, Notes — drives free-subscriber growth that Kit, built around automation and commerce rather than discovery, doesn't try to replicate. A fee saving that costs you a growth channel can be a bad trade; this math covers costs, not distribution, and the reverse move prices that network as a premium. Compare the fee profiles directly at Kit and Substack, or see how leaving Substack looks toward a flat-fee platform in switching to beehiiv.

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