Thailand's BOI Pipeline: How Promoted Investment Is Rewiring Where You Source

The Board of Investment has approved billions in new promoted projects across electronics, autos, and machinery, a forward-looking signal that today's BOI certificate is tomorrow's factory. Here is what the promoted-investment data actually says about where Thai capacity is heading, vertical by vertical, against Vietnam, Malaysia, and Indonesia.

When buyers ask whether Thailand has the capacity to make a given part, they usually reach for the Department of Industrial Works registry, the list of operationally-licensed plants. That list is real, but it is backward-looking. By the time a factory appears in DIW it is already running; for fast-moving sectors the DIW snapshot under-reports the true industrial base by two to three years. The Board of Investment (สำนักงานคณะกรรมการส่งเสริมการลงทุน) data tells the opposite story. BOI captures everything from initial approval through certificate issuance, including projects still under construction. A BOI certificate today is, in effect, a DIW factory tomorrow. For anyone deciding where to source, or where to place a plant, the BOI pipeline is the leading indicator that matters.

The promoted-investment dataset, drawn from BOI approvals and certificates via the government's open-data portal, covers 151 approval-quarter rows and 140 certificate-quarter rows spanning calendar years 2020 through 2023. It does not name companies, the Thai government publishes only aggregated project counts and investment value per activity group per quarter. But the aggregate is enough to read the direction of the country's industrial build-out with confidence.

Where the promoted money is going

BOI organizes promoted activity into broad groups. Across all years in the dataset, the largest single concentration of approved capital sits in electrical appliances and electronics, at roughly ฿1.3 trillion across 2,646 approvals, the deepest pool of any manufacturing-facing group. Metals and materials follow at ฿702.8 billion (2,711 approvals), machinery and vehicles at ฿614.0 billion (1,694 approvals), and chemicals and petrochemicals at ฿473.5 billion (1,279 approvals). Agriculture, food and biotech draws ฿680.0 billion, and the broad utilities group the largest figure of all at ฿1.7 trillion. The signal is clear: Thailand's promoted base is anchored in electronics and heavy industry, not just assembly.

The pipeline is bigger than the installed base

The most useful way to read BOI is to set the latest-year promoted pipeline against the factories already operating. The Ministry of Industry registry counts 5,228 active Thai factories across all sectors. When you compare that operational base, vertical by vertical, against the latest-year BOI project counts, the gap reveals where Thailand is building rather than where it has already built. The pattern is not steady-state growth, in several verticals it is a surge, with the approved pipeline running multiples of the current installed base.

Electric-vehicle batteries are the most extreme case: just 4 active EVB factories operate today, against roughly 221 latest-year BOI projects, a pipeline some 55 times the installed base. Semiconductors show 19 operating factories against about 199 promoted projects, a pipeline roughly 10.5 times current capacity. PCB is an emerging vertical with no DIW base yet but roughly 166 promoted projects worth about ฿41.6 billion. Autos surge too, 157 operating factories against about 772 promoted projects (฿881.1 billion), nearly five times the installed base. Even the steadier verticals are growing: HVAC at about 3.5 times its base, solar at about 4.8 times. Machinery, with 292 operating factories against about 331 promoted projects, reads closest to steady-state.

“A BOI certificate today is a DIW factory tomorrow. For sourcing decisions, the promoted-investment pipeline, not the operational registry, is the leading indicator that matters.”

Reading the pipeline vertical by vertical

The latest-year per-vertical split (calendar 2023) puts hard numbers behind the surge. Auto leads at about ฿881.1 billion across roughly 772 projects, with machinery at about ฿377.6 billion (331 projects). Inside the electronics group, the within-group split, apportioned using the BOI Investment Promotion Strategy 2023-2027 weighting, places EVB at about ฿55.4 billion, semiconductors at about ฿49.9 billion, and PCB and data-center equipment each at about ฿41.6 billion. Other electrical, HVAC, and solar round out the tail. These splits are approximations: the BOI taxonomy is not granular enough to perfectly separate SEMI from PCB from EVB inside the electronics group, and a BOI approval is not yet an operational factory, the pipeline narrows as projects advance from approval to certificate to DIW licensing.

What survives that caveat is the shape. The verticals where Thailand is adding the most promoted capacity relative to what exists today, EVB, semiconductors, autos, PCB, are precisely the ones where a buyer betting on future Thai supply is betting with the grain of national industrial policy, not against it. The verticals reading closer to steady-state, like machinery, are where the existing base is already the story.

Thailand against the Southeast Asian field

The promoted pipeline only means something in regional context, because buyers choosing a manufacturing location are choosing between Thailand and its neighbors. The data-center vertical is the clearest comparator captured in our research: Thailand's approved capacity pipeline exceeded 2.87 GW as of September 2025, 3.7 times Indonesia's planned capacity. That same EEC corridor concentration shows up in the supplier base. Across the verticals we have mapped, the Thailand-corridor share of known suppliers runs highest where the build-out is hottest: about 57% in EVB, about 43% in semiconductors, and about 42% in auto, versus thinner shares in DC (about 10%) where the supplier universe still skews US and EU.

For a buyer or a supplier weighing Thailand against Vietnam, Malaysia, or Indonesia, the BOI pipeline is the part of the decision Thailand controls: a deliberate, policy-backed surge of promoted projects concentrated in a single industrial corridor, dense enough that cluster co-location and same-corridor fulfillment become real advantages rather than marketing. The neighbors compete on cost and on their own incentive regimes; Thailand's distinguishing bet is the density and forward velocity of its promoted electronics-and-mobility base.

Three honest limits apply to all of the above. The dataset counts new promoted projects, not the cumulative stock. The within-electronics vertical split is a weighted approximation, not a clean count. And a promoted project is a forward signal, not a guarantee, some approvals never reach certificate, and some certificates never reach DIW licensing. Used as a direction-finder rather than a ledger, though, the BOI pipeline is the single best public read on where Thai capacity is heading.

What it means for sourcing decisions

• Read BOI before DIW. The operational registry tells you what exists; the promoted-investment pipeline tells you what will exist 2-3 years out, the horizon most sourcing and plant-location decisions actually run on.
• Bet with the surge. EVB (~55× installed base), semiconductors (~10.5×), and auto (~4.9×) are where Thailand is adding the most capacity relative to today, sourcing roadmaps in these verticals are betting with national policy, not against it.
• Treat PCB as emerging, not absent. ~166 promoted projects worth ~฿41.6B are building a vertical with no prior DIW base, early supplier relationships here are formed before the registry catches up.
• Use corridor density as a tiebreaker vs. neighbors. Thailand’s 2.87 GW DC pipeline (3.7× Indonesia’s) and high Thailand-corridor supplier shares in EVB (~57%), semi (~43%), and auto (~42%) are the cluster advantages Vietnam, Malaysia, and Indonesia cannot replicate by incentive alone.
• Discount the pipeline honestly. Approvals are not factories; the within-electronics split is approximate; numbers are new flow, not cumulative stock. Use BOI as a direction-finder, and confirm any single supplier against operational evidence.