Local laws reflect the fact that Pakistan is a Muslim country. You should respect local customs and sensitivities at all times, especially during the holy month of Ramadan or if you intend to visit religious areas. For more general information see
Travelling During Ramadan.
You should dress modestly at all times. Men and women should cover their shoulders and legs when in public. Women should cover their heads when entering mosques or other holy places, and when travelling in more rural areas.
If you or your father were born in Pakistan, you might be considered a Pakistani national by the authorities, even if you do not hold a Pakistani passport, and the British government might be prevented from providing the full range of consular assistance.
Consular assistance in remote areas might be delayed.
For identification purposes you should carry a photo id at all times. Keep a photocopy of the data page and Pakistani visa from your passport plus copies of other important travel documents. These should be kept separately from the originals, and copies left with friends or relatives in the UK.
Importing alcohol and pork products is illegal. Homosexuality and co-habitation by an unmarried couple are illegal. Possession of even small quantities of illegal drugs can lead to imprisonment. Drug smuggling can attract the death penalty.
Do not take photographs at military establishments, airports or any infrastructure, including bridges and dams or from aircraft. In the past British nationals have been arrested on suspicion of 'spying'. You should seek prior permission from any official present if you are photographing these types of places, especially in border areas.
For more general advice for different types of travellers see
Your Trip.