Hiking permits or visas. These are important for crossing the borders as you may run into a ranger who will check.
Passport or Identification. To go with the permits.
Cash. As mentioned in the things to know section, everywhere is cash only and there is nowhere to withdraw cash once you are in the mountains.
Travel insurance info. Just in case the worst were to happen.

Accessories

55 litre backpack. This was perfect for me, if not slightly too big. I wouldn’t recommend anything larger.
Navigation GPS or phone app. We used Gaia GPS on the phone to plot a course and keep us on track. Most of the trail is well marked, however there are some parts where this absolutely saved us.
LifeStraw filter water bottle. The water is generally fine here, but these water bottles are fantastic and give me peace of mind.
Sunscreen. Its hot, make sure you’re protected.
Sunhat. Trust me, it’s very hot.
Camera. It’s extra weight, but I love capturing moments on the hike with my camera.
Drybag. Even in summer the weather turns quickly. We got caught in a few downpours and this kept my essentials dry.
A good pair of hiking boots. I found this an absolute must with the terrain that we were crossing. They saved me a few rolled ankles.
Bar of laundry soap. We washed out clothes every night and this was a must for us.
Blister plasters and tape. Trust me, you will eventually need these.
Imodium and sickness pills. We were lucky but there was a bit of sickness going around, so just to be safe.
Electrolytes and multivitamins. Your immune system often takes a hit whilst hiking and these helps to keep you going.
Cash. As mentioned in the things to know section, everywhere is cash only and there is nowhere to withdraw cash once you are in the mountains.
General toiletries. Trust me, you will want a shower after each day.
Insect repellent. To keep the mosquitos at bay.

Clothing

X2 short sleeved sports tops. Make sure that they breathe well. I just rotated these, washing one each night.

X2 hiking shorts. Same as the tops, just washed one each night.

X3 pairs of hiking socks. I washed each night and kept one pair for emergencies or if they didn’t dry.

X5 pairs of underwear. I washed most nights, but these often took a bit longer to dry.

X1 Jumper or sweater. Whilst it’s hot during the day, it can get cold at night.

X1 Waterproof raincoat. This is a must as the weather can turn very quickly. We met some people who got caught in a storm without one and they looked pretty miserable.

X1 hiking pants. These were good for cooler days or if there was long scratchy bush we were walking through.

X1 Togs. There are lots of rivers and watering holes that you can stop at along the way.