I would consider the risk of being mugged, prostitutes and being called names, the dangers of public transport are hardly scams and certainly these may occur anywhere. I'd only have to go to London to experience some of the above!
New arrivals are probably most at risk, as those who have been in Kenya for some time are more wary and aware of common scams. Foreigners, particularly white are assumed to be rich.
Arguably the most common scam is being overcharged for goods and services. As mentioned above; taxi rides is a common one. The advice is to always negotiate the price before getting in, use a pre-booked service (online) is an alternative. There is a 'bargaining culture' in Kenya and the locals will always negotiate the price, so don't feel embarrassed to do likewise. Also be prepared to walk away.
Uber; some people report being scammed or overcharged, or having to add tolls to the fare. However, the drivers are paid peanuts and are forced to work long hours to compensate - I don't blame them on the whole.
Property scams. This is also common and can lead to significant financial losses. Expect things like being charged for property that doesn't exist, fake title deeds for the 'sale' of land/property by someone other than the owner, plots that don't exist, plots/property being sold that stands on land that has been snatched years ago, foreigners being sold land which is for agricultural use (foreigners cannot purchase agricultural land, except through a registered company with a majority Kenyan shareholding).
For property rental, always go through a reputable agent and visit the property in person. Ask about service charges and who will pay these. Ask who the owner is. Find out the frequency of rent payments - some landlords was quarterly payment upfront. Tenancy laws are similar to those in the UK, so the contract would be familiar to anyone from there.
Land/property purchase. Don't do anything without being in Kenya! If its a plot, ensure that it is listed as residential. Visit it in person and ask to be shown the beacons (these define the size of a plot) and if you have the resources, measure the plot to ensure the size is as advertised. Get a reputable lawyer who will do due diligence and carry out a search back to the original land owner.
If purchasing an apartment off plan, there is a risk that the finished apartment may not be quite like the drawing, or the on site facilities are different (worse). Visit the site personally before handing over any cash. Be aware that neighbouring plots might be subsequently developed, blocking any view. Never accept an apartment until you have personally inspected the standard of work. If in Nairobi, check the reliability of the water supply. Again, have a reputable lawyer who will do a thorough due diligence on the property and the developer.
If purchasing a completed property, most of the above still applies. If purchasing in a developing area, be aware that shops, multi occupancy low cost housing etc, may be built adjacent.Â
Never give a lawyer a deposit (20% is usual) to hold in an escrow account, as you may find that it disappears. We have in the past opened a temp joint account (all parties to sign) with the current property owner and done the final transfer of funds whilst sitting in the bank with the current owner - its worked for the several properties that we have bought and sold.
Mobile phone MPesa scams. These are often run by prisoners. There is the usual text with a link, encouraging you to click on this - just don't. Common scams involve being contacted by someone who claims to be from the phone company requesting a reversal of an MPesa transaction (funds sent in error to you). It is so easy to be sucked into this, and send the 'funds'. Check the number of the caller and check your MPesa account for any transfer. SIM swap scam. Someone gets hold of your number and convinces Safaricom that you have lost the SIM for that number and provide a new SIM, giving the scammer access and control of your device, MPesa, online banking etc. You can however request that a replacement SIM can only be obtained in person - this effectively eliminates the online scam, as the SIM swap is blocked.
Immigration scams, I am not aware of any specific scams, but there will be no end of people willing to 'help' with immigration matters. Immigration lawyers will charge substantial sums. Immigration is a major corruption avenue, as for obvious reasons, applicants really want the permit that they are applying for. Bribes are rife and high cost. Applications are submitted online which is supposed to reduce the corruption, but really doesn't.  At the very least, staff can and will spin out applications where no bribe has been paid and expedite those where a bribe has been paid.
There are plenty of the usual pyramid schemes and get rich quick investment scams that you can get anywhere.
