Bitcoin following forks

Another really basic question from a newbie…
After experimenting with small amounts, I purchased some BTC with the intent of just holding on to them over an extended time period, stored in several paper wallets, now sat in my filing cabinet.
I now read of various forks, including the Segwit2x later this month. So my question is, without really understanding the fork process, will my existing paper BTC wallets still be valid in several months/years time without the need to do anything, when I decide to exchange/sell these back to my local currency, GBP?

Yes, your wallets will still exist on the BTC blockchain and contain the funds, and your private keys will still give you the ability to control those funds.

The creation of new forks of the chain / code do not invalidate your wallet - they just create new places where you can go and (potentially) use that same private key to access new funds.

NOTE: You must be VERY careful before doing this, because using your private key to access those new funds exposes the key. If some new piece of software (or site) copies your private key when you use it, then they have your private key, and can use it to control your original BTC.

The safest way to handle this:

  1. Move your old BTC into a new wallet with a new private key.
  2. Use the old private key on the forked chain to access your forked coins.

This way, if someone steals the private key as you try to handle the new coins, what they’ve “stolen” is the ability to access your old BTC wallet, which you’ve already emptied. (Note: they may still be able to steal your forked coins. Be sure you’re using a safe system and software.)