Barclays Smart Investor has received the worst customer score of all time for investment platforms from Which? Money readers.
Our annual survey of investment platforms comprised ofunique reviews and ratings for 12 leading brokers based on a survey of 2113 Which? members.
We reveal why Barclays came bottom of the pack, as well as the platforms that customers loved and how broker fees measure up.
In the latest survey, Barclays Smart Investor received a customer score of just 33%, making it the lowest-scoring investment platform in the five years we have polled users on this topic.
Users criticised the new platform, a successor to Barclays Stockbrokers, for the length of time it has taken to transfer their assets - with some saying it has taken up to three months, leaving customers unable to buy or sell investments.
One user said: 'The move has been nothing less than catastrophic.'
'The new service is appalling, with most of the good parts of the previous offering being replaced with a truly inferior alternative.'
When approached by Which? for comment, Barclays said it has waived the final fee relating to the old service for all customers, and that it did not start charging fees for Smart Investor until November 2017, having launched it in August last year.
Harry Rose, editor of Which? Money, said: 'Clearly Barclays' customers feel badly let down by its new platform and this has been reflected in its abysmal customer score - the worst we've seen.
'People who are disappointed with their current broker should prioritise the services that matter to them most and shop around to see if their current broker offers value for money. If your portfolio has increased in value you may be overpaying and it could be time to switch.'
Customers of HL enjoy the range of research available to them and the easy-to-use website, as well as direct access to a customer service line.
One survey respondent said: 'The platform is easy and quick to use, and presents good information about current holdings and values.
'Any queries I've had seem to be quickly resolved by HL helplines.'
The only gripe with HL tends to be value for money, because it charges an annual fee of 0.45%, which penalises those with bigger portfolios.
For investors with portfolios of up to £10,000, HL is a good option because charges are a percentage rather than a fixed fee. This means you get the high-scoring services and customer experience for less money than you could pay elsewhere.
Youinvest charges a percentage in the same way as HL, but significantly lower at 0.25%. The Share Centre, on the other hand, charges a fixed £4 plus VAT per month for an Isa (£57.60 total per year).
At £50,000, the brokers charging fixed amounts start to overtake those charging a percentage as the most cost-effective choice. is the cheapest for a £50,000 portfolio of funds, assuming two trades a year (although most brokers don't charge to trade funds).
Once you pass £200,000, The Share Centre becomes an even more appealing choice. It came joint second place in the table, and received four stars for several crucial criteria, including value for money, clarity of charges, and customer services.