Osome vs. Sleek vs. Monx

• “They make so many mistakes. They have made 2 mistakes in my financial statements! Can you believe that? They can’t even get the basics right. This is a MAJOR RED FLAG.”
• “Working with Osome is painful. The money you save working with Osome will cost you x5 more in time wasted with them given how bad everything else is.”
• “Their people are not trained. They must be relying a lot on AI tools and cheap staff. As a result, their people don’t even know what they are talking about most of the time.”
• “They communicate very poorly. They keep using internal jargon yet expect their clients to understand what they are talking about.”
• “I am currently a client with them and they are about to file my taxes late, only after getting a letter from the government saying they have not received my tax return.”
• “The absolute worst service. They wanted to charge me £100 for a confirmation statement which I did myself for £34. They failed to provide any accounting software.”
• “Their customer support is unavailable most of the time, or uses AI/Chatbots, or staff copy/pasting information from Google when it is available.”

The Automation Problem

Osome’s heavy reliance on automation and AI means less human oversight. While this might reduce their costs, it frequently leads to errors that real accountants would catch. Multiple UK clients report incorrect tax calculations, missed filings, and poor communication from undertrained staff.

One customer described the experience: “Oh the thrill of getting your VAT calculated 90 minutes before you need to pay £99k in tax… Be able to argue, that the tax in reality should be £5k, not £25k – and discover that you were indeed RIGHT and the accountants was WRONG.”

Hidden Costs

While Osome advertises competitive pricing, UK customers report surprise charges appearing on their accounts. One reviewer noted: “Not to mention the surprise £3k charge that appears on your account out of nowhere for a period 1.5 years ago.” Several customers report being charged £100 for confirmation statements that cost £34 to file directly with Companies House.

Common Complaints

• “Post-onboarding, the service was shockingly poor. Fast with sales, slow and poor with service during incorporation + assistance in account opening.”
• “Their team is unprofessional, response times are unbearably slow, and the service overall is just terrible.”
• “Slow response times. Took a month for the company to complete my registration.”
• “Response times can stretch to 2-5 days” – with some plans requiring you to wait even longer

The Modularity Trap

While Sleek advertises flexibility, their modular pricing structure means you need to carefully piece together services. The registered address (legally mandatory in the UK) requires renewal fees. Neither is adequate company secretary support for multiple shareholders always included.

By the time you add everything you actually need, Sleek’s “affordable” package becomes significantly more expensive—and you still don’t get the responsive, human-centric support that Monx provides as standard.

Support Limitations

• Response times: 2-5 business days depending on plan tier
• Phone support availability is limited (multiple reviews mention “no one ever answers the phone”)
• No weekend support
• Some reviewers report dealing with multiple staff members without proper handover

• “Oh the thrill of getting your VAT calculated 90 minutes before you need to pay £99k in tax… The wonder if having to explain ‘I don’t have unpaid invoices, check again’ every quarter. Be able to argue, that the tax in reality should be £5k, not £25k – and discover that you were indeed RIGHT and the accountants was WRONG.”
• “After moving to a new accountant, we discovered that Osome has been making mistakes all over our financial statements for the past 2 years. A ton of financials were categorised incorrectly, leading to incorrect taxation.”
• “I’ve had 5 accountants since joining. I’d wake up to automated messages like ‘Meet your new accountant’ and be passed to someone completely new who didn’t know a thing about our business.”
• “Documents were lost because the person handling my case left the company… I got a letter from the tax department about an overdue tax amount. By the time I got the letter, it was already too late.”

Glassdoor Employee Reviews

Based on employee reviews, Osome faces significant internal challenges:

• 3.1/5 star rating with only 40% of employees recommending the company to a friend
• Multiple mentions of staff handling 80-200 clients each
• Reports of “absurd workload” with accountants being “burnt out and extremely understaffed”
• UK operations described as “deprioritised” with growth focus continuing in Asia

When even the employees aren’t happy, it’s reflected in the quality of client service.

Additional Limitations:

• Support only available Monday-Friday (UK business hours)
• Phone support can be difficult to reach—multiple reviews mention “no one ever answers the phone”
• No weekend availability
• Some customers report: “There have been countless times where I’ve had to follow up on things myself, when that is what I thought I paid Sleek to help me remind of.”

As one reviewer notes: “Response times are unbearably slow, and the service overall is just terrible. The amount we paid for their services it’s felt like a complete waste of money and time.”

❌ With “cheap” providers:

Low base price + Hidden fees + Penalties for missed deadlines + Cost of fixing errors + Time wasted on poor communication = Much higher real cost