If you wish to follow the small salary big dividend method of rewarding yourself from your own company, this simple guide can help.
As a matter of routine, your company should prepare its own corporation tax reserve. You will probably need to prepare a personal income tax reserve as well. A company can only pay dividends from the company’s post tax profit. If you have no profit then you can pay no dividends. Do not pay out all of the profit as dividend, only the post tax profit. That means that …

Since the introduction of the Dividend Allowance and the Interest Allowance in 2016, compounded by the new Scottish rates of tax in 2017, there is no easy way to work out the optimum pattern of salary and dividends for directors of small UK companies.
Here’s a rough guide to what you might want to pay yourself and what sort of personal income tax reserve you may need to keep. Remember, that this is in addition to your company preparing its own corporation tax reserve. A company can only pay dividends from …

Your UK VAT registered business can get a refund of EU VAT for most goods and services you buy for your business.

You cannot normally reclaim GST and VAT from countries outside the EU. Nor can you reclaim EU VAT if the expense is not wholly and exclusively for the purposes of your business.
Moreover:

you need a proper VAT receipt from the actual supplier, addressed to your business, showing the rate of VAT charged and the exact amount of VAT charged
a “proforma invoice” is not a proper VAT receipt
what you can reclaim …

HMRC has recently (late summer 2017) introduced a system for issuing “dynamic tax codes for PAYE cases”. It is intended, from their point of view, to be more accurate and thereby give taxpayers the most suitable code on a regular basis. Indeed it does seem to issue regular updates to coding notices (a bit too regular by some standards) and it does seem to get some things wrong! So in that respect it’s no better than the system they had before.

Every time your employer runs a payroll, and submits one …

“Making Tax Digital” is a new system of filing your tax data quarterly, and it will eventually replace the Self Assessment system.
In effect, you will have to file a quarterly tax return if you fall into one of these categories:

self employed
partnership
landlord

And having filed all four quarterly tax returns, you will also be required to complete a fifth tax return with any year end adjustments (or simply to confirm that the earlier four were correct and that there are no year end adjustments). So that’s five tax returns every year, instead …