All accounts start as trial accounts and can be used for free for thirty days. Your trial account will have an expiration date of thirty days from the date it was created.
If you find W2H to be a good fit for your needs, you can pay at any time, and your trial account is converted to a paid subscription and your expiration date is extended by the duration you choose when you pay. There is no penalty for paying before your expiration date.
All of your trial account data is saved and you can continue to use the account you set up.
If later on you need a higher helper level, you can choose to upgrade and pay a prorated amount or choose to move up your expiration date.