You second question does not seem to follow on from the first as you have moved from sales to purchases. As the rules differ it really forms a separate question.
This answer assumes you are VAT registered and dealing in standard rated goods and services.
If you purchase goods from a UK based, VAT registered supplier you will by charged UK VAT.
If you purchase goods from a supplier in another EU Member State you will not be charged VAT. You must provide them with your VAT registration number. You should also account for acquisition VAT on your UK VAT return (it goes into box 2 on the return). You can claim this VAT back on the same return subject to the normal rules.
If you purchase goods from outside the EU you will have to pay VAT (and possibly duty) when the goods enter the UK. HMRC should issue you with a VAT paid certificate by post. This acts as your purchase invoice to allow you to recover the import VAT.
If you buy services from providers outside of the UK and they do not charge you VAT, you should account for output VAT under the reverse charge mechanism. This gets added into box 1 on the return and can be reclaimed subject to the normal rules.
If you are selling goods to persons within the UK you must account for UK VAT.
If you are selling goods to persons in another EU member state you will need to know whether they are VAT registered and using the goods for a business purpose.
- If they provide you with a VAT registration number you can invoice without VAT. You will need to have evidence that the goods left the UK.
- If they are not VAT registered you must charge them UK VAT.
If you are selling goods to someone outside of the EU, you do not charge VAT (regardless of whether they are in business or not). You will need to have evidence that the goods have left the UK.
The taxation of services will depend upon the nature of the services. For example, if you are undertaking work on goods located in the UK then UK VAT is chargeable but if you are supplying advertising services to a customer outside of the UK then UK VAT is not chargeable.