Scriptures mention about three type of Karmas 1. Sanchita (accumulated) 2. Prararbdha (already ready to bear fruits) and Vartamana (the current ongoing Karmas).
Among these, the fruits of the Prarabdha Karmas are to be experienced while living on earth. The fruits of the Sanchita Karmas are to be experienced in the future, meaning in the afterlife i.e. either in Heaven/Hell or in the next births. Same is true for the deeds that we are currently doing (the Vartamana Karmas). They are like seeds being sown on the ground. Their fruits will have to be experienced by the Jiva possibly in the afterlife (and not in this).
From Devi Bhagavatam's Chapter 21 (Book 4):
19-20. Effort, application and manifestation of energy are certainly
the duties of man; but their effects are all under the Great Destiny
or Fate. The Pundits knowing the ancient lore say that there are three
kinds of Karma mentioned in the Purânas and Âgamas :-- First, the
Sanchita Karma (done in past births); the Prârabdha Karma, the Karma
already done; and the Vartamân Karma (Karma in hand).
21. The Karma, auspicious and inauspicious, done in many previous lives and preserved in seed forms, remains always inherent in a human
soul. Urged on by this Karma, the Jîvas quitting their previous
bodies, enjoy Heaven or Hell as effects of these, their own acts.
22-23. According to their good or bad works, the Jîvas acquire the
higher happy body and enjoy various pleasures in the Heavens, or they
take up very painful vicious bodies and suffer various pains in hell.
24-25. At the expiry of the above period in Heaven or Hell, when there
comes the time of his assuming another body, the Jîva becomes
conscious of the subtle body (Linga Deha) and takes his birth again.
When the Linga Deha comes into existence, the part of the Karma done
in various previous births that are ripe and ready to yield their
fruits, gets attached to the Jîva by God (or Destiny).
26. Therefore the collective effect of Karma done in previous births always exists in a Jîva’s body. O Fair-eyed One! The effects of
Prârabdha Karma, ripened and ready to yield their fruits must have to
be experienced by a Jîva, whether happy or unhappy.
- O beautiful young woman! Penances, performed according to rules, destroy the effect of Karmas that are in hand and are weak (i.e., not
yet accumulated strongly as to remain in seed forms).
- The Prârabdha Karma, those acts out of all the previous acts done in previous births that are fully mature and ready to yield their
fruits, cannot be averted; their effects must have to be experienced
and then they can die away; they cannot be expiated by penances or any
other remedial measures. Therefore you must hand over unconditionally
your new born babe unto the hands of Kamsa.
As mentioned in the passage, Sanchita Karmas are the deeds done by the Jiva in the previous births. Among these Karmas, some amount may have become Prarabdha by now. Fruits of those have to be experienced in this life only and those of the remaining part in the afterlife/next births.