"I can't control spend when I scale a campaign" is one of the most common frustrations among teams running online advertising. Platform algorithms move fast, auctions are unpredictable, and the standard Maximum Delivery strategy can quickly drive up cost per conversion during periods of high competition.
Cost Cap is designed to solve exactly that problem.
In this article, we break down how Cost Cap works, when to use it, how to calculate the right target, and how to build the campaign infrastructure around it so moderation and ad accounts do not become bottlenecks when you scale.
What is Cost Cap, and how is it different from Maximum Delivery?
| Maximum Delivery | Cost Cap | |
|---|---|---|
| What it is | A bidding strategy where the algorithm aims to spend the full budget to generate as many impressions, clicks, or other results as possible, without strict CPA control. | A goal-based bidding strategy where TikTok optimizes delivery so the average cost per target action, or CPA, stays at or close to the target you set. |
| Type | Spend-based: the focus is volume, while CPA may fluctuate. | Goal-based: the focus is CPA control, even if volume is lower. |
| When to use it | Scaling when volume matters, such as launches and promotions. It is also useful for Traffic, Reach, and Conversions campaigns when you need to collect early data. |
Budget efficiency and stable CPA. Best suited to controlled scaling.
💡 Cost Cap is especially valuable during highly competitive periods. When the auction heats up and uncontrolled CPA can double, Cost Cap helps keep performance within plan.
|
| Risks | CPA can rise because delivery becomes more aggressive. It is not ideal when ROI needs to stay within a strict range. | Low volume if the cap is too tight. The algorithm may also learn more slowly. |
TikTok recommends Cost Cap as the main strategy for advertisers who care more about CPA predictability than pure volume.
Why Cost Cap matters when you scale
Imagine this: a campaign is performing steadily with a budget of $500 per day and an $8 CPA. You increase the budget to $2,000, and CPA starts climbing: $12, $15, $20. The budget gets spent, but the plan falls apart.
This is the logic of Maximum Delivery in action. When the budget increases, the algorithm starts reaching less relevant users in order to spend it.
Cost Cap solves this structurally. When you increase the budget, the system continues working within the CPA target you set and prioritizes impressions for users who are most likely to convert at the required price.
Successful Cost Cap use cases
Impulse, a brain training app
Impulse tested Smart+ with Cost Cap against a regular campaign under fully identical conditions: budget, targeting, creatives, and bidding strategy. The only difference was Smart+ versus non-Smart+.
Over two weeks:
- CPA decreased by 25%
- Budget spend increased by 125%, meaning the algorithm used the available budget more efficiently
GAC, an automotive brand in Kazakhstan
Chinese car manufacturer GAC used Smart+ with Cost Cap to optimize spend and concentrate delivery on a more relevant audience.
- Cost per click decreased by almost 30%
- Cost per impression decreased by more than 20%
- Reach among interested users increased while costs went down
Source: TikTok for Business Wrap-up 2025, Kazakhstan ->
Kooapps / Snake.io, mobile gaming
Casual game publisher Kooapps launched Smart+ with Cost Cap to promote Snake.io in the US market. The CPI target was set based on actual performance over the previous seven days, following the same logic described above.
Results compared with a control campaign without Smart+:
- CPI decreased by 56%
- ROAS increased by 2x
- CTR increased by 18%
- Budget utilization increased by 20x
Cost Cap: supported formats and objectives
Cost Cap is especially relevant for teams focused on web conversions and lead generation, two formats with a direct, measurable return.
We recommend using Cost Cap in Smart+ campaigns. Smart+ gives TikTok's algorithm more room to optimize: the system automatically tests audiences, placements, signals, and delivery patterns in real time.
In this model, Cost Cap is not just a bid limit. It works as a dynamic target.
Cost Cap in a Smart+ campaign
Bidding strategy: Goal-based bidding only: Cost Cap and Target ROAS.
Advertising objectives in Smart+:
- Smart+ Lead Generation: lead generation through a website
- Smart+ App Promotion: app promotion
- Smart+ Sales with a website or app as the sales destination
Budget type: Daily Budget only.
How to use Cost Cap: 3 scenarios
A new ad group in a new campaign
When creating a new ad group in TikTok Ads Manager, select Cost Cap in the Bidding and Optimization section and enter your target CPA. The strategy activates immediately.
An existing ad group already using Cost Cap
If the ad group is already running on Cost Cap and you want to scale it, simply increase the budget. The cost-control mechanism will continue to work.
An existing ad group using Maximum Delivery
There are two options here:
Preferred option: use Hybrid Bidding, a feature that lets you switch the bidding strategy on an active ad group without recreating it. This preserves the algorithm's accumulated learning history. After switching to Cost Cap, increase the budget.
Alternative option: if CPA has already increased and the campaign has "broken", do not stop the ad group. Switching through Hybrid Bidding can help restore efficiency while preserving engagement history.
Warning: Hybrid Bidding does not support the Product Sales objective for Shop.
Which "Target CPA" should you set when configuring Cost Cap?
The logic is simple.
If you already have conversion data, use the average CPA from your current campaigns over the last seven days. This is your starting point.
If you have limited data or the campaign is new, first run Maximum Delivery for 7-14 days, collect at least 50 conversions, and record the resulting CPA. Then move to Cost Cap using that value as your target.
How to check whether the target is realistic:
- Daily budget should be at least 10 x your target CPA. For example, if the target is $10, the budget should start from $100 per day. If the budget is lower, the campaign may not exit the learning phase.
- If the campaign is not spending, the target is too low. Increase the bid in 20% steps until you reach the required volume.
- If CPA stays consistently below the target for several days in a row, you can carefully reduce the target by 10-15% and lock in the new efficiency level.
Scale the campaign gradually, increasing budget by no more than 20-50% at a time. Do not change the target if CPA is above goal during the first 3-5 days: the algorithm needs time to adapt. A sharp bid reduction during this period will usually collapse spend rather than fix CPA.
Let's look at an example. Suppose you are running lead generation for an online school. For two weeks, the campaign ran on Maximum Delivery and collected 60 conversions at an average CPA of $12. You switch to Cost Cap and set the target at $12-13. You do not lower it immediately; you use the actual value. The daily budget is $150, which is above 10x the target. During the first three days, CPA stays at $14-15 as the algorithm adjusts. That is normal. On day four, CPA drops to $11. After a week, the campaign's average CPA is $12.4 and the budget is spent in full. You decide to scale. You increase the budget from $150 to $180, or +20%. CPA does not react and stays around $12-13. Another week later, you increase the budget to $216. The result is the same. In total, the budget increased by 1.5x, while CPA stayed within plan. This is exactly how Cost Cap should work.
What would have happened with Maximum Delivery: when the budget increased from $150 to $216, the algorithm would likely have started reaching a less relevant audience, and CPA could have risen to $18-22. You might have received more conversions on paper, but the campaign economics would have broken.
Evido by Aitarget: reliable infrastructure for launching TikTok Ads
Bid setup is only one part of working with online advertising. The Cost Cap strategy helps solve the problem of scaling campaigns without burning through budget.
The other part is having a working ad account that will not be blocked in the middle of a campaign, plus support that can respond quickly when something goes wrong.
Evido by Aitarget is an official TikTok Marketing Partner, and this is exactly what we provide. We are not an agency that runs campaigns for you. We are a partner that gives you the infrastructure to work effectively.
What you get:
- Verified ad accounts with lower risk of bans and sudden account blocks
- AI-driven pre-moderation for creative assets, helping reduce the risk of rejections before platform moderation
- 0% commission, so you pay only the ad budget, with no markup for access to a TikTok ad account
- Support from certified specialists throughout your time with us, including help with long moderation times, rejected assets, and technical issues
- A TikTok Ads knowledge base and team expertise, built on practical experience and real cases, not just help-center documentation
-> Try TikTok Ads through the Aitarget platform
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