Royal Mail advice for addressing envelopes

Write an address (or stick labels) on the left of envelopes to enable the Royal Mail scanners in their sorting offices to give the best performance. Addresses not written correctly may be rejected by the scanner and set aside for manual sorting which causes delays.

• The name and address go on the bottom left corner of the front of the envelope or parcel. 

• Use clear and easy to read handwriting (or font if you are printing the address). 

• Use a pen or ink that is clear against the colour of the envelope or parcel. 

• Left align the text (no centred or 'stepped' lines). 

• No commas or full stops. 

• Leave a generous margin around the address. 

• Place the correct postage on the top right. 

Source: https://help.royalmail.com/personal/s/article/How-to-address-your-mail-clear-addressing-tips