A falling uphold rate, but on far fewer decisions
Monzo Bank Ltd's uphold rate in published Financial Ombudsman decisions fell to 10.3% in the most recent 90-day window, down from 13.4% in the prior window, a drop of 3.1 percentage points. On its own that looks like a continuation of a well-established trend. But the number of decisions behind it fell even faster: from 272 in the prior 90-day window to 131 in the current one, a drop of 141 decisions, or 51.8%. Both windows meet Veste's minimum sample threshold of 30 decisions, so the comparison is not simply too small to discuss, but the sharp fall in volume means each individual case now carries more weight in the percentage than it did a year ago.
This matters because a 3.1 percentage point movement calculated over 131 decisions is a different proposition to the same movement calculated over several hundred. With fewer cases in the denominator, a handful of finely balanced decisions going one way rather than another can shift the published rate more than the underlying pattern of complaints may justify. Veste's uphold rate definition, provided in the underlying data, is (upheld cases plus half of partially upheld cases) divided by the total, so both fully and partially successful complaints for consumers contribute to the published percentage.
The numbers in full
Across the entire published history captured for Monzo, 2,795 decisions have been recorded, running from the bank's first appearance in the data on 12 September 2018 to its most recent published decision on 28 May 2026. Of those, 508 were upheld in full, 478 were partially upheld and 1,809 were not upheld, giving an overall uphold rate across the whole period of 26.7%. That compares with a uphold rate of 28.8% across the entire corpus of 400,172 decisions Veste holds, so Monzo's all-time rate sits marginally below the corpus-wide baseline, though the gap is modest.
The year-on-year figures show a clearer pattern than the single 90-day comparison. In 2022, Monzo's published uphold rate was 39.8% across 275 decisions. In 2023 it was 37.5% across 372 decisions. In 2024 it fell to 34.9% across 737 decisions. In 2025 it dropped further to 17.2% across 933 decisions. So far in 2026 it stands at 12.6% across 301 decisions. Each of these annual samples meets the minimum threshold, so the year-on-year series can be read with reasonable confidence as a genuine multi-year decline rather than noise from small numbers.
What the monthly series shows
The monthly trend data, covering 25 months from May 2024 to May 2026, gives a more granular view of how this decline has unfolded and adds useful context to the latest quarterly figures. In May 2024, Monzo's uphold rate stood at 30.8% on 13 decisions. It fluctuated through the summer and autumn of 2024, reaching 39.6% in November 2024 on 53 decisions, one of the higher points in the series. From early 2025 the rate begins a more consistent slide: 30.4% in January 2025, 25.4% in February, 23.7% in March, then falling further to 18.3% in April and 18.8% in May. By September 2025 the monthly rate had fallen to 10.2% on 132 decisions, the highest single-month volume in the whole 25-month series. Rates in the 10-12% range have persisted since, including 11.2% in October 2025, 11% in November 2025, 11.8% in December 2025, and figures in that broad band through into 2026: 17.1% in January, 11.9% in February, and 9.7% in March, the lowest monthly rate in the series. The two most recent months, April and May 2026, show 15.4% and 10% respectively, but on very small monthly totals of 13 and 10 decisions, too few to draw firm conclusions about a single month in isolation.
What this monthly pattern shows is that the 90-day period comparison is not an isolated blip. The decline visible in the quarterly figures sits within a longer downward slope that has been running for well over a year, from uphold rates regularly above 30% in mid-to-late 2024 to rates consistently below 15% for most of the period since September 2025.
Volume matters as much as rate
The volume story running alongside the rate decline is equally worth setting out plainly. September 2025 saw 132 decisions published, the largest monthly total in the series. Volumes stayed elevated through the autumn: 85 in October, 82 in November, 102 in December. They remained substantial into early 2026, with 82 in January, 88 in February and 108 in March. Then volumes fell sharply: just 13 decisions in April 2026 and 10 in May 2026. This collapse in monthly totals is the direct driver of the 51.8% fall in decisions between the prior and current 90-day windows, and it is worth being cautious about reading too much into a percentage calculated on a shrinking base. The published-decisions series is not the same thing as the volume of complaints made to the firm; it reflects how many cases the Ombudsman has closed and published in a given period, which can lag or cluster for reasons unrelated to underlying complaint volumes.
What is behind the pattern, and what is not shown
The supplied case examples, all decided in late May 2026, illustrate the kinds of disputes making up Monzo's current caseload without proving anything about the wider trend. Three of the four examples concern account closures or Cifas fraud marker registrations following suspicious payments into customer accounts, and all three were not upheld, with the Ombudsman finding in each case that Monzo had reasonable grounds for its actions. The fourth and fifth examples concern overdraft lending decisions, both also not upheld, with the Ombudsman finding Monzo's affordability checks reasonable and proportionate in each instance. These five examples cannot explain a shift affecting hundreds of decisions across two years, but they are consistent with the broad category data available: account closure disputes show a 12% uphold rate across 455 decisions, and irresponsible lending disputes show a 27.6% uphold rate across 147 decisions, both figures drawn from Veste's related-category dataset rather than specific to Monzo alone.
Other categories in the same dataset show materially higher uphold rates. Fraud reimbursement disputes under the APP scam framework carry a 32.1% uphold rate across 1,507 decisions, service failures generally carry 32.9% across 140 decisions, and credit file or adverse marker disputes carry 30.1% across 93 decisions. Card and payment disputes sit at 19.3% across 334 decisions. These figures describe categories across the wider dataset, not Monzo-specific breakdowns, so they cannot be used to explain why Monzo's rate has moved as it has. They are useful only as a reminder that uphold rates vary substantially by complaint type, and that a firm's overall rate depends heavily on the mix of complaint categories it happens to attract in a given period.
Reading the numbers with appropriate caution
It is worth restating what the 90-day comparison can and cannot support. The fall from 13.4% to 10.3% is real in the sense that both figures are calculated from the same consistent methodology and both samples clear the minimum threshold Veste applies before making comparisons. But a 3.1 percentage point movement on a base of 131 decisions, down from 272, is the kind of shift that could plausibly arise from ordinary month-to-month variation in case mix rather than any change in how Monzo handles disputes or how the Ombudsman assesses them. The year-on-year figures, spanning far larger samples of several hundred decisions each, offer stronger grounds for saying something structural has changed since 2022, when the rate stood at 39.8%, through to 2026 so far at 12.6%. Even so, this remains a description of published Ombudsman decisions, not a measure of the total volume or nature of complaints Monzo receives, and it says nothing about the proportion of Monzo customers who complain in the first place.
It is also worth noting, as a matter of methodology rather than criticism, that firms are recorded in this data under the exact business name attached to each decision. Subsidiaries of the same banking group are not merged, so any comparison drawing on similarly named entities elsewhere in the market would need to treat them as distinct.
The longer view
Taken together, the annual series from 2022 to 2026 describes a five-year decline in Monzo's published uphold rate from close to 40% to close to 12%, running alongside a rise then a sharp fall in the number of decisions published each month. The most recent 90-day movement is consistent with that longer decline in direction, but it should be read as one more data point in a multi-year pattern rather than a fresh development in its own right, particularly given how much the underlying sample size has shrunk in the same period. Anyone tracking Monzo's Ombudsman record should watch whether monthly volumes recover from the very low April and May 2026 totals, since a return to the volumes seen in early 2026 would give more statistical weight to whatever uphold rate follows.
Methodology
This analysis covers 2,795 published Financial Ombudsman decisions naming Monzo Bank Ltd as the respondent business, spanning 12 September 2018 to 28 May 2026. The uphold rate is defined as (fully upheld decisions plus half of partially upheld decisions) divided by total decisions, consistent with Veste's standard definition. The 90-day period comparison uses windows anchored to the newest decision date in the corpus rather than the calendar publication date, because the Ombudsman publishes decisions in arrears; both the current window (131 decisions) and prior window (272 decisions) meet Veste's minimum sample size of 30. The year-on-year series covers 2022 to 2026, with all years meeting the minimum sample threshold. The monthly trend series covers 25 months from May 2024 to May 2026. The baseline uphold rate across Veste's full corpus of 400,172 decisions is 28.8%. Published Ombudsman decisions are not the same population as all complaints made to a firm, and category-level uphold rates cited are corpus-wide figures, not Monzo-specific breakdowns.