Thameswater vs United Utilities: most-reported complaints compared
Most-reported issues at Thameswater and United Utilities, according to reviewers on Trustpilot — classified by our automated reader and backed by verbatim quotes from distinct reviews. This is a side-by-side of what reviewers report, not a score, rating or recommendation for either company.
Thameswater
TrustScore 3.9 · 6,271 reviews on Trustpilot.
602 reviews analysed, 2016-05-31 to 2026-11-09.
Complaint rate (recent window): 38%
93% of negative reviews get a company reply.
“I've been waiting 5 months for a revised bill from Thames Water.”
United Utilities
TrustScore 4.7 · 8,629 reviews on Trustpilot.
2,207 reviews analysed, 2026-06-20 to 2026-11-12.
Complaint rate (recent window): 7%
99% of negative reviews get a company reply.
“had 3 engineers visit. Neither know the cause of the problem. They are going to change the stop tap, but don't think that is the problem.”
Reported on both
Issues with an evidenced category (at least two verbatim quotes) on both sides.
| Issue | Thameswater | United Utilities |
|---|---|---|
| Support unhelpful | 52% | 31% |
| Billing errors | 39% | 14% |
| Poor core service | 23% | 43% |
| Support unreachable | 17% | 10% |
Method: reviews are classified into a fixed complaint taxonomy by an automated reader; every category shown is backed by at least two verbatim quotes from distinct reviews. Figures are census classifications, not official statistics, and reflect what reviewers reported — not findings of wrongdoing by either company. Not affiliated with, endorsed by, or sponsored by Trustpilot A/S, Thameswater or United Utilities.