Thailand Rental Electricity Survey 2026: 98.8% of Advertised Rates Exceed the 4.88 THB/Unit Cap
A systematic random sample of 400 rental listings across 46 Thai provinces (July 2026), comparing real advertised electricity rates against the OCPB official calculation-method cap — with the full price distribution, an open reproducible methodology, and declared limitations.
In a systematic sample of 400 rental/dorm listings across 46 Thai provinces (July 2026), 254 advertised a numeric electricity rate — and 251 of those 254 (98.8%, 95% CI 96.6–99.6%) advertised a rate above the OCPB official calculation-method cap of 4.88 THB/unit. The median advertised rate is 7 THB/unit = 1.43× the cap. This figure covers only listings that advertise a rate — not all rentals (another 23% say "call to ask") — and advertised rates can differ from what a contract actually charges.
Key Findings at a Glance
of advertised rates exceed the 4.88 cap
251/254 listings (95% CI: 96.6–99.6%)
THB/unit median advertised rate (1.43× the cap)
P25–P75 = 7.0–8.0 THB/unit
of Bangkok advertised rates over the cap (provinces 97.9%)
Bangkok 108/108 · provinces 143/146
THB/mo median excess at 30 units (≈763 THB/yr)
vs the 4.88 cap · max observed 453.6 THB/mo
How Advertised Rates Are Distributed
This chart shows all 254 advertised electricity rates. The red line marks the OCPB official calculation-method cap of 4.88 THB/unit — only 3 listings (1.2%) sit at or below it, and not a single one advertised at or below the residential blended average of 3.95 THB/unit. The most common prices are 7 and 8 THB (together 68.1% of all listings).
| Price range (THB/unit) | Listings | Share |
|---|---|---|
| ≤ 3.95 (residential avg) | 0 | 0% |
| 3.95 – 4.88 (within cap) | 3 | 1.2% |
| 4.88 – 5 | 11 | 4.3% |
| 5 – 6 | 36 | 14.2% |
| 6 – 7 | 84 | 33.1% |
| 7 – 8 | 92 | 36.2% |
| 8 – 9 | 19 | 7.5% |
| 9 – 10 | 5 | 2% |
| > 13 (outliers, see limitation #5) | 4 | 1.6% |
Is your room paying above this 7-baht median? Compare against the cap and the real utility rate in seconds.
Check yours now — free rental electricity checkerThe Invisible Electricity Price: A Third of Listings Don't Advertise One
Of all 400 sampled listings, only 63.5% advertise a numeric electricity rate that a tenant can see before making contact. For the rest, tenants must call to ask — or only learn the real rate at contract time:
The "direct utility meter" group pays the utility's actual bill and is treated as approximately compliant — it is excluded from the over-cap denominator. The 23% "call to ask" group is the market's biggest information gap: nobody sees those prices until they ask.
Bangkok vs the Provinces: Over-Cap Nationwide
Overcharging is not a Bangkok-only phenomenon — the median advertised rate is 7 THB/unit nationwide, and the over-cap share is nearly identical:
| Metric | Bangkok | Provinces (45) |
|---|---|---|
| Sample size | 166 (41.5%) | 234 (58.5%) |
| Advertise a numeric rate | 65.1% (108) | 62.4% (146) |
| Median / mean (THB/unit) | 7.0 / 7.57 | 7.0 / 7.41 |
| P25–P75 | 7.0–8.0 | 7.0–8.0 |
| Share above the 4.88 cap | 100% (108/108) | 97.9% (143/146) |
The most-sampled provinces after Bangkok: Chonburi (31), Chiang Mai (23), Pathum Thani (16), Phuket (15), Nonthaburi (14), Nakhon Pathom (13). A per-university-zone breakdown needs a larger targeted sample and is planned for the next survey wave.
How Much Extra Per Month: A 30-Unit Simulation
Assume a single room using 30 units/month (typical for a rental room without all-day aircon). This table computes the monthly excess for every advertised rate, against the OCPB calculation-method cap of 4.88 and against the current-period residential blended average of 3.95 THB/unit:
| Statistic | vs cap 4.88 (n=251) | vs residential avg 3.95 (n=254) |
|---|---|---|
| Median | 63.6 THB/mo | 91.5 THB/mo |
| Mean | 78.98 THB/mo | 105.79 THB/mo |
| Maximum observed | 453.6 THB/mo | 481.5 THB/mo |
The upper half of over-cap listings (P75) overcharge by 93.6 THB/month or more, and the median excess of 63.6 THB/month works out to roughly 763 THB/year per room — the more units you use (aircon), the bigger the multiple. To get your own number, plug your real units into the rental electricity checker or see the step-by-step rental bill guide.
Bonus: Water Charges Raise the Same Question
The same survey also recorded water charges: 45.2% advertise a per-unit price (n=180 valid), median 18 THB/unit (P25–P75 = 17–23.5, max 100), and another 11% charge a flat per-person fee, median 100 THB/person/month (range 50–300).
The OCPB rule's principle for water is "no more than the rate the provider actually charges" (ไม่เกินอัตราที่ผู้ให้บริการเรียกเก็บ) — there is no single numeric water cap like the electricity figure. Because waterworks tariffs are tiered by usage, judging any individual listing as "over" requires a per-case usage-band comparison, so this report shows the distribution only and passes no per-listing judgment (see limitation #6).
Methodology (Fully Reproducible)
This report's credibility rests on its open methodology: the data source, sampling frame, selection rules, and every limitation are disclosed in full below.
Sampling frame: all rental/apartment listing pages in the public sitemap of a major public Thai rental-listings website (its robots.txt permitted full access on the collection date) — 18,304 URLs at collection time (22–23 Jul 2026, Thailand time). Every sampled unit is an apartment/dormitory listing.
Sampling: stratified systematic — the 4 sitemap files form 4 strata of 100 samples each, step = ⌊N/100⌋, starting offset = SEED mod step, with SEED = 20260723 (the collection date — publicly verifiable, no manual cherry-picking). All 400 samples collected successfully (0 failures), 404 total requests, ≥2.1 s between requests.
| Stratum (sitemap) | Frame size N | step | offset | Sampled |
|---|---|---|---|---|
| 1 | 5,000 | 50 | 23 | 100 |
| 2 | 5,000 | 50 | 23 | 100 |
| 3 | 5,000 | 50 | 23 | 100 |
| 4 | 3,304 | 33 | 10 | 100 |
Fields recorded: the advertised electricity/water charge type and rate exactly as published on each listing page (numeric rate / call-to-ask / direct utility meter / included in rent), plus province and district only.
Counting rules: the over-cap denominator is listings advertising a positive numeric rate only (n=254) · the direct-utility-meter group is reported separately as "approximately at the real rate" and excluded from the denominator · call-to-ask / included-in-rent listings are excluded from price statistics · no manual data removal — every outlier is retained and declared (limitation #5).
Privacy & fairness: the dataset stores no property names, URLs, listing IDs, coordinates, or addresses below district level, and only aggregate statistics are published — this report neither identifies nor accuses any individual property. Comparing against the cap compares advertised numbers with the official calculation method; it is not a per-case legal finding.
Reference figures: 4.88 THB/unit = the cap per the OCPB official calculation method (the 2568 Contract Committee notification — landlords may not charge above the utility's actual rate; 4.88 is the figure from the official worked calculation) · 3.95 THB/unit = the current-period residential blended average (incl. Ft), used as the "approximate real rate" reference. Legal details on the rental electricity law page.
Download the aggregate data (CSV) for media/researchers — cite as "CapSolar Rental Electricity Survey, Jul 2026" with a link back to this page.
Download CSVLimitations (Read Before Citing)
Every number in this report comes from real, reproducible automated collection — but six limitations must be understood by anyone citing it:
Self-selection bias — price statistics cover only the 63.5% of listings that chose to advertise a rate. The real rates of the 23% "call to ask" group are unknown; the bias direction is uncertain, though common sense suggests they are unlikely to be cheaper than rates owners are willing to publish.
Platform bias — the sample comes from a single listings website, skewed toward urban apartments/dormitories; older dorms and rooms never listed online are not represented.
Advertised ≠ actually charged — this survey measures public price-advertising behavior; a listed rate may be outdated or differ from what the lease actually charges.
Frame drift — sitemap contents and ordering change daily; exact listing-level replication requires same-day collection, but all sampling parameters (SEED, step, offset, positions) are recorded, so statistical replication is possible.
Outliers — 4 listings (1.6%) advertise 17–20 THB/unit, possibly bundling other fees or data-entry errors. We did not remove them, and the result is insensitive to them: excluding them, the over-cap share is still 98.8% (247/250).
Water comparison basis — waterworks tariffs are usage-tiered, so a per-listing "over" judgment requires a usage-band comparison; this report shows only the water price distribution and passes no per-listing judgment.
Next Update
This survey will be repeated quarterly with the same method (SEED = that wave's collection date) to track how the over-cap share moves as OCPB enforcement tightens. The next wave will add targeted sampling of major university zones and a detailed comparison of water charges against official tiered rates.
About This Survey
Produced by the data team at CapSolar, a solar energy provider in Thailand that regularly publishes verifiable public data on Thai electricity rates (such as the Factory Electricity Cost Index and consumer electricity guides). This survey is public-interest data with no sales content; media and researchers are welcome to cite it with a link back.
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