TikTok Upgraded Smart+ Web Conversions: PM Guide

What Changed

TikTok replaced the legacy Smart+ Campaign Creation API with a three-endpoint structure: /v1.3/smart_plus/campaign/create/, /v1.3/smart_plus/adgroup/create/, and /v1.3/smart_plus/ad/create/.¹ The legacy /campaign/spc/create/ endpoint stopped accepting new campaign creation on March 31, 2026.² Legacy update and status-check endpoints remain functional until June 30, 2026.² The Manual Campaign Management API creation endpoint is scheduled for deprecation on December 31, 2026.²

The restructured API separates campaign, ad group, and ad into independent objects, which enables up to 30 ad groups per campaign compared to the legacy limit of 1.¹ Each ad group can carry its own budget, targeting, and optimization settings when Campaign Budget Optimization (CBO) is turned off.¹

Prerequisites and Dependencies

Access requires allowlisting — a TikTok sales representative must enable the feature for each advertiser account.¹ Three developer app permissions are needed: Ads Management > Upgraded Smart Plus Ads, Reporting > Upgraded Smart+ Report, and Creative Management > Creative tool.¹

Web Conversions campaigns require either a TikTok Pixel or the Events API to be installed and firing the target conversion event.³ The LANDING_PAGE optimization goal works only with the Pixel; the Events API alone does not support it.¹ When both Pixel and Events API are active, event deduplication uses the event_id field and matches events received within a 48-hour window.⁵

Optimization Goals and Billing

All Web Conversions campaigns bill on Optimized Cost Per Mille (OCPM).¹ Three optimization goals are available: CONVERT (optimizes toward a specified conversion event), LANDING_PAGE (optimizes toward landing page views, Pixel-only), and CLICK (optimizes toward link clicks).¹

Cost Cap bidding is available only with daily budgets, not lifetime budgets.¹ TikTok recommends setting daily budgets at a minimum of 10x historical CPA, with 30x as the target for Target CPA or Minimum ROAS bid strategies.⁴

CBO vs Non-CBO Decision

When CBO is enabled, TikTok distributes the campaign budget across ad groups automatically.¹ CBO imposes a uniformity constraint: all ad groups within the campaign must share identical values for promotion_type, optimization_goal, optimization_event, billing_event, bid_type, bid_price, conversion_bid_price, deep_bid_type, vbo_window, and roas_bid.¹

When CBO is off, each ad group carries its own budget and can target different optimization goals or events independently.¹ Use CBO when testing multiple audience segments against the same conversion event; use per-ad-group budgets when ad groups target different optimization events or require isolated spend control.

Targeting: Automatic vs Manual

Automatic targeting delegates audience selection to TikTok's algorithm.³ It splits into two layers: "Audience Controls" (constraints the system guarantees, such as geo and age floors) and "Audience Suggestions" (hints the system may or may not follow, such as interest categories).¹

Manual targeting gives direct control over demographics, interests, behaviors, and custom/lookalike audiences at the ad group level.¹ Manual targeting is available only in the Upgraded Smart+ API; the legacy Smart+ API supported automatic targeting exclusively.¹

Creative Constraints

Each ad supports up to 50 creative assets combined across video, carousel, and TikTok Post formats.¹ Carousel ads accept up to 35 images plus 1 music track.¹ Up to 5 ad text variations and up to 3 standard CTAs can be assigned per ad.¹

Spark Ads (ads that boost organic TikTok posts) and non-Spark ads cannot coexist in the same campaign.¹ Identity types for Spark Ads include CUSTOMIZED_USER, AUTH_CODE, TT_USER, and BC_AUTH_TT.¹

Learning Phase

After launch, TikTok recommends making no edits to a campaign for 7 days to allow the learning phase to complete.⁴ After the learning phase, bid adjustments should stay within 15% of the current value and occur no more frequently than every 2 days.⁴

Migration Planning

What breaks and when:

• March 31, 2026: The legacy /campaign/spc/create/ endpoint rejects new campaign creation requests.² Existing legacy campaigns continue to run.
• June 30, 2026: Legacy update (/campaign/spc/update/) and status endpoints stop functioning.² Any automation relying on these endpoints must migrate before this date.
• December 31, 2026: The Manual Campaign Management API creation endpoint is deprecated.²

Fallback path: Between March 31 and June 30, 2026, legacy campaigns already created can still be updated and monitored through the old endpoints.² No new legacy campaigns can be created after March 31, 2026.²

PRD Checklist for Product Managers

1. Confirm allowlisting with TikTok sales rep before development begins.¹
2. Verify Pixel or Events API fires the target conversion event in production.³
3. If using both Pixel and Events API, implement event_id for deduplication.⁵
4. Decide CBO vs per-ad-group budgets; if CBO, enforce the 10-field uniformity constraint in campaign creation logic.¹
5. Enforce the 30 ad group per campaign limit in any UI or automation layer.¹
6. Enforce the 50-asset-per-ad and 35-image carousel limits in creative upload flows.¹
7. Prevent mixing Spark and non-Spark ads within a single campaign.¹
8. If using Cost Cap bidding, restrict budget type to daily (not lifetime).¹
9. If using LANDING_PAGE optimization goal, require Pixel (Events API alone is insufficient).¹
10. Plan learning-phase lockout: block edits for 7 days post-launch, then cap bid changes at 15% per 2-day interval.⁴

Stakeholder Summary

The Upgraded Smart+ Web Conversions API adds three capabilities the legacy API lacked: multi-ad-group campaigns (up to 30 per campaign), per-ad-group budget and targeting control, and manual targeting for web conversion objectives.¹ Creative flexibility increased to 50 assets per ad with up to 5 text variations and 3 CTAs.¹ The migration is mandatory, with the first hard deadline on March 31, 2026 for new campaign creation.²