CAC payback period is the time it takes the net revenue from a cohort of paying subscribers to repay what it cost to acquire them. For a subscription app, calculate it from the cohort's cumulative net revenue per subscriber, month by month, and find the month it crosses your acquisition cost. Do not use the SaaS shortcut of CAC divided by monthly revenue, which assumes nobody cancels. How fast should paid growth pay back? There is no universal answer, and published benchmarks range from 60 days to twelve months. The right target is the longest payback your cash can fund at the spend you plan, and never longer than the cohort age for which you have real retention data.
Below is the method, a worked example showing how far the shortcut and the dashboard can mislead, what payback does to your bank balance once store payout timing is included, and how we would set a target for apps at different stages. Every number in the worked examples is hypothetical and labelled as such. Published figures come from RevenueCat's State of Subscription Apps 2026 and from Apple's and Google's own documentation.
What CAC payback period measures
Payback is a cash metric. It does not tell you whether a subscriber is profitable over their lifetime. That is the job of the ratio we covered in LTV:CAC for subscription apps, which has no clock in it. Payback tells you how long each pound of acquisition spend is tied up before it is free to buy the next subscriber, and so how much growth the business can finance.
Three definitions need fixing before the number means anything.
- The cost. Paid media CAC per paying subscriber, or fully loaded with creative and fees. Our guide to calculating subscription app CAC sets out the versions. Whichever you choose, it must be cohorted by acquisition date, not divided by last month's spend.
- The revenue. What reaches you after store commission, sales tax and refunds.
- The start of the clock. You pay for media when the install happens. Revenue starts when the user converts, which for a trial app is days or weeks later. RevenueCat's 2026 report finds 50.6% of paid conversions happen on the day of install and 19.2% in week six or later. The clock starts at install.
The CAC payback formula, and why the SaaS version breaks
SaaS shortcut: payback months = CAC ÷ monthly revenue per customer
Subscription app version: payback month = the first cohort age at which cumulative net revenue per paying subscriber is equal to or greater than CAC per paying subscriber
The shortcut is what most guides in the current search results give, and it works when customers keep paying at a steady rate. Subscription apps do not behave like that. RevenueCat's report puts the median first renewal rate for monthly plans at 53% to 61% across categories, which means close to half of monthly subscribers never make a second payment. Its median retention after six months on monthly plans is 14% to 26%, and after a year 6% to 14%. A formula that assumes every subscriber pays every month is wrong by more in month two than most teams' entire margin of error.
The correct version needs a retention curve, which means it needs cohort data. That is not a flaw. It is the point: payback is only knowable from what cohorts actually pay.
Worked example: one monthly plan, three answers
This app is hypothetical. It sells a £9.99 monthly subscription through the UK App Store, including 20% VAT. In a subscriber's first year Apple keeps 30% of the price before VAT, so each payment nets £5.83, and after a year of paid service the rate rises to 85%, or £7.08 a payment, per Apple's subscription terms. We assume 3% of first payments are refunded. Of every 100 subscribers, 57 make a second payment, 23 are still paying after six renewals and 11 after twelve, which sits inside RevenueCat's median ranges above without being anyone's real curve.
Here is the payback month for four levels of paid CAC, measured three ways. Month 0 is the first payment.
| CAC per subscriber | SaaS shortcut (CAC ÷ £5.83) | Dashboard (before commission and VAT, with churn) | Real (net, with churn) |
|---|---|---|---|
| £15 | 2.6 months | Month 1 | Month 4 |
| £20 | 3.4 months | Month 3 | Month 8 |
| £25 | 4.3 months | Month 4 | Month 14 |
| £30 | 5.1 months | Month 6 | Not within two years (£29.72 recovered by month 23) |
Look at the £20 row. The shortcut says three and a half months. A dashboard that reports revenue before commission and VAT says month 3. The two quick answers agree with each other, which is what makes them convincing. The cash says month 8. All three are calculated correctly from their own inputs, and a team steering by either of the first two would scale a channel that ties up money for more than twice as long as they think.
The dashboard gap is not hypothetical. RevenueCat's own documentation says its realised LTV is calculated from revenue minus refunds and still includes what the stores deduct for commission and tax. For a UK App Store subscriber in their first year the developer receives about 58% of what the customer paid. We walk through the netting by store and market in our guide to break-even CPI for subscription apps, and the same table applies here. For EU storefronts, Apple's new business terms from 1 October 2026 set a 26% commission on In-App Purchase, falling to 15% for auto-renewing subscriptions after their first year.
Notice also how non-linear the real column is. Moving CAC from £20 to £25 adds six months to payback, because by month 8 the cohort has shrunk to about a sixth of its starting size and each extra pound of cost has to be recovered from far fewer people. On a monthly plan, the last few pounds of CAC are the expensive ones.
Annual plans: payback is close to all or nothing
Now the same hypothetical app selling a £59.99 annual plan instead. The first payment nets £33.94 after Apple's 30%, VAT and a 3% refund allowance. If 30% renew at month 12, within RevenueCat's median first renewal range of 23% to 40% for annual plans, each renewal nets £42.49 at the 85% rate.
| CAC per subscriber | Net recovered per original subscriber | Payback |
|---|---|---|
| £30 | £33.94 at conversion | Day of conversion |
| £40 | £33.94 at conversion, £46.69 after the first renewal | Month 12 |
| £50 | £46.69 after the first renewal | Not before the second renewal at month 24 |
There is no month 4 or month 8 on an annual plan. Either the first net payment covers CAC and payback is immediate, or nothing more arrives until the renewal and payback jumps to a year. That makes the first payment, net, the single most important number for an annual-plan app's acquisition budget, and it makes the first renewal rate a question of whether the business works at all at higher CAC.
Two cautions. First, this compares cash timing, not customer quality. People who choose an annual plan may be more committed than people who choose monthly, so pushing everyone onto annual will not necessarily reproduce these numbers. Second, Apple's 85% rate applies after a year of paid service, and free trial days do not count towards it, so a long trial delays the better rate slightly.
What payback does to your bank balance
Payback month is a per-subscriber figure. The number your finance lead cares about is the cash low point when you run that payback at a real spend level, and there is one more delay most payback models leave out: the stores do not pay you when the subscriber pays them. Apple pays proceeds within 45 days of the last day of the fiscal month in which the transaction completed. Google Play pays out around the 15th of the following month. Meanwhile you pay for media as it runs.
Take the hypothetical app spending a steady £30,000 a month on Meta. We model the store payout as arriving two months after the subscriber pays, which is roughly where Apple's schedule lands.
| Scenario (hypothetical, £30,000 a month) | Cash low point | Recovery |
|---|---|---|
| Monthly plan, £20 CAC, revenue counted when the subscriber pays | About £74,000 down at month 8 | Back to zero at month 20 |
| Monthly plan, £20 CAC, revenue counted when the store pays out (two month lag) | About £134,000 down at month 10 | Still about £27,000 down at month 24 |
| Annual plan, £30 CAC, revenue counted when the store pays out (two month lag) | £60,000 down at month 2 | Back to zero at month 15 |
Two findings from that table are worth stating plainly. An eight month payback at £30,000 a month needs well over £100,000 of working capital once payout timing is included, which is more than four months of the ad budget itself. And an app that pays back on the day the subscriber converts is still £60,000 out of pocket at the low point, because two months of media have been paid for before the first store payout lands. Day-zero payback is not the same as self-funding growth.
This is the calculation that should set your payback target. Not a benchmark. Build the cumulative cash curve for the spend you plan, find the low point, and compare it with the money you actually have.
What is a good CAC payback period for a subscription app?
The published answers disagree with each other. Adapty's guide to customer acquisition cost lists 60 to 90 days as typical for subscription apps. Admiral Media's payback guide says most healthy subscription programmes land between six and twelve months, with the strongest nearer five to seven. Neither states the data behind its range, and the second is close to David Skok's SaaS metrics guidance, that many of the best SaaS businesses recover CAC in five to seven months and that profitability looks anaemic beyond twelve. That guidance was written for B2B software. RevenueCat's 2026 report, the largest public dataset on subscription apps, does not publish a payback benchmark at all; payback appears only in contributors' commentary.
So 60 days and twelve months are both being presented as normal for the same kind of business. Our worked example shows why a single figure cannot work: the same app, with the same users, pays back on day zero on an annual plan at £30 CAC and in month 14 on a monthly plan at £25. Plan mix, price, store, market and renewal rate move the answer further than any category average can capture.
Our view is that a good payback period meets three tests.
- It is net. Measured after commission, tax and refunds, from install, by cohort.
- It is observed. It is no longer than the oldest cohort age for which you have real retention data. A twelve month payback built on four months of observed renewals is a forecast, not a payback.
- It is fundable. The cash low point at your planned spend, including store payout timing, fits inside your cash with room to be wrong.
Why the right target depends on funding and runway
Two apps with identical cohorts can rightly choose different payback targets. The difference is what the money costs them and how long they can wait. This is how we would frame it.
| Situation | The question that sets the target | Our working view |
|---|---|---|
| Self-funded, ad spend paid out of revenue | Can the cash low point be covered without touching payroll or reserves? | Short. Ideally the first net payment covers CAC, and the store payout lag is the only gap you finance. |
| Funded, 18 months or more of runway | Does the cash low point at planned spend fit comfortably inside runway, with room to be wrong? | Can run longer, but never beyond the cohort age where retention has actually been observed. |
| Raising in the next six to nine months | Will cohorts acquired now have visibly paid back before the round? | Shorter than the runway alone would allow, because investors will look at realised cohorts, not forecasts. |
| Profitable and scaling | What does the marginal block of spend pay back in, not the average? | The average can stay healthy while the last £10,000 stretches well past target. |
The last row matters more than it looks. Payback reported as a blended average across all spend hides the fact that each extra block of budget buys more expensive subscribers. In the monthly example, the step from £20 to £25 CAC added six months. If scaling pushes the marginal CAC up by that much, the marginal payback can be past your limit while the average still looks fine. We cover marginal cost in more detail in the LTV:CAC guide.
Retention sets the payback more than the ad account does
On a monthly plan, the first renewal is the biggest single input. Holding everything else in the worked example constant at £20 CAC, a first renewal rate of 53% pays back in month 9, 57% in month 8 and 61% in month 7. That is the full spread of RevenueCat's category medians, worth two months of payback with no change to media cost at all.
Commentary in RevenueCat's report makes the same point from the retention side. Subscription consultant Alice Muir Kocourková notes that retention jumps 18 to 30 percentage points between the first and second renewal across plan durations, which is why the first billing cycle is where most of the damage is done. For paid acquisition this has a direct consequence. The message in the ad sets the expectation the product has to meet by the first renewal, and creative that overpromises buys cheap installs whose payback never arrives.
The cost side responds to work done after the install too. In the Steps & Beasts case study, heavy creative testing and onboarding changes lifted install-to-subscriber conversion, and revenue rose 145% with active subscriptions up 118%. The case study does not publish a payback period and we will not invent one. What it shows is that the cost per paying subscriber falls when more of the people the ads bring in actually convert, which shortens payback without the media getting any cheaper.
What a payback target changes inside a Meta account
Nobody can run a Meta account against a number that arrives eight months later. The payback target has to be translated into checkpoints the account can be judged on in days.
- Derive the early target from the curve. In the monthly example at £20 CAC, a cohort on track for an eight month payback has recovered only about 28% of its cost from first payments. The annual example at £30 recovers more than 100% on its first payment. One Day 7 ROAS target applied to both would kill the first and flatter the second, so set the checkpoint from the payback curve you need, by plan mix.
- Convert it into a cost per trial. Most accounts optimise to trial starts or purchases, not revenue. Working backwards from the CAC your payback allows, through trial-to-paid, gives a cost per trial target creative can be judged against within a week. Our trial-to-paid benchmarks help sanity check that conversion step.
- Expect iOS to report late. On iOS, attributed conversions arrive with privacy delays, so early payback reads in Meta will understate the cohort. Our guide to SKAdNetwork postback delays explains the timing. Use your own revenue data, cohorted by install date, as the source of truth for payback.
- Gate budget increases on marginal payback. Raise spend in steps and judge each step on the cohorts it bought, not on the account average.
If you are unsure which of these numbers to act on first, our comparison of CPI, CPA and CAC for subscription apps sets out which metric answers which question, and when each one becomes readable.
Five questions to ask of any payback number
- Is revenue net of store commission, sales tax and refunds?
- Does the clock start at install or at conversion?
- Is it built from real cohort retention, or from an assumed churn rate?
- Is the CAC paid media only, or fully loaded, and is it the average or the marginal spend?
- What is the cash low point at the spend you plan, once store payout timing is included?
Frequently asked questions
What is CAC payback period for a subscription app?
CAC payback period is the time it takes for the net revenue from a cohort of paying subscribers to repay what it cost to acquire them. Net means after store commission, sales tax and refunds. It is measured from acquisition, by cohort, and it answers a cash question rather than a profitability one: how long is the money spent on acquisition tied up before it comes back?
How do you calculate CAC payback period for a subscription app?
Take one acquisition cohort, add up the net revenue it produces month by month per paying subscriber, and find the first month in which that cumulative figure is equal to or greater than the cohort's acquisition cost per paying subscriber. The SaaS shortcut of CAC divided by monthly revenue per user assumes nobody cancels, which is not true of any subscription app, so it understates payback, often by several months.
What is a good CAC payback period for a subscription app?
There is no reliable universal figure. Published guidance ranges from 60 to 90 days (Adapty's CAC guide) to six to twelve months (Admiral Media's payback guide), and neither states the data behind it. RevenueCat's State of Subscription Apps 2026 does not publish a payback benchmark. A good payback period is one your cash can fund at the spend level you plan, measured on net revenue, and no longer than the cohort age for which you have actually observed retention.
Should CAC payback be calculated on gross or net revenue?
Net. Subscription dashboards usually report revenue before store commission and tax. For a UK App Store subscriber in their first year, where the price includes 20% VAT and Apple keeps 30%, the developer receives about 58% of the price the customer paid. Calculating payback on gross revenue can make an eight month payback look like a three month one.
Do annual plans pay back faster than monthly plans?
In cash terms, usually yes, because the full year's price arrives at once. If the first annual payment, net of fees and refunds, exceeds CAC, payback happens the day the subscriber converts. If it does not, nothing more arrives until the first renewal twelve months later, so annual payback is close to all or nothing. That is a statement about cash timing. Users who choose annual plans may differ from users who choose monthly ones, so switching your plan mix will not necessarily reproduce the same economics.
How does CAC payback period relate to Day 7 ROAS?
Day 7 ROAS is an early checkpoint and payback is the destination. The checkpoint that predicts a given payback depends on plan mix. In a hypothetical monthly-plan app with an eight month payback, the first payments recover only about 28% of acquisition cost, while an annual-plan app can recover more than 100% on its first payment. A single Day 7 ROAS target applied to both would kill one and flatter the other, so derive the checkpoint from the payback curve you need.
The short version
CAC payback period is a cash clock, and for a subscription app it has to be read off a net cohort curve rather than calculated with a SaaS shortcut. In our hypothetical monthly app the shortcut said three and a half months, the dashboard said three and the cash said eight. On annual plans payback is close to all or nothing, decided by whether the first net payment covers CAC. Store payout timing means even immediate payback needs working capital. Published benchmarks range from 60 days to a year without showing their data, so the useful target is your own: net, observed and fundable at the spend you plan.
For how payback fits the wider growth system, read our subscription app marketing strategy guide. If you want Meta acquisition run against a payback target built this way, our consumer apps page explains how we work with subscription apps, and if your app is already spending, our pricing is published.