Being a sole trader (self-employed) vs company

Opening year rules -> most likely overlap profits	NO opening year rules.
Losses can be used against total income of:  the year of the loss AND/OR the previous year.  the three years prior the year of loss starting with the earliest one.  future income of the same trade.	Losses can be used against income of:  loss relief can be used against total profits (current year first, then 12 months back)  future income of the same trade.
Losing 10% tax credit on dividends as no company.	10% tax credit is available to shareholders
Personal allowance is available.

Example,
Annual Revenue in 2015/2016 = 25,000 gbp
How much cash after taxes will be left for one and only trader/shareholder/owner ?

(1) Sole trader		(2) Company
Revenue	25,000		25,000
less: trading related expenses	[assume] (9,000)	less: trading related expenses	[assume] (9,000)
		Less: salary (no PAYE, NIC for company and employee)	(8,060)
Net income	16,000
less: Personal Allowance	(10,600)
Taxable profit	5,400	Taxable profit	7,940
[within basic rate band] -> 20% of tax  5,400 x 20%	(1,080.00)	small company tax rate = 20%  7,940 x 20%	(1,588)
NIC on 16,000gbp Class 2	(145.60)	Available to pay out as dividend	6,352**
Class 4 (16000-8060) x 9%	(714.60)	** Amount will be tax free for the shareholder due to 10% tax credits

Conclusion:
Option (1) As a sole trader will take home 14,059.80 (10,600 + (5,400-1,080)-(145.60+714.60)).
Option (2) Via company owner will take home 14,412 (8,060 + 6,352).

It is better to choose option 2 as it will give 352.20gbp (14,412.00 - 14,059.80) more after taxes.          

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PS. Obviously better option will depend on a number of variables. Above is a simple example for a simple trader. To help you to choose the best option for YOU, please get in touch (see contact details).