fall back on
phrasal verb.phrasal verb. to use something as a backup plan when your first choice fails.
phrasal verb. to resort to a secondary resource or alternative plan when the primary option is no longer available or successful; implies a sense of security or a safety net.
If I don't get the job, I can fall back on my savings.
When the GPS stopped working in the mountains, they had to fall back on an old paper map.
The government was forced to fall back on emergency reserves after the primary supply chain was disrupted by the strike.
usually followed by a noun representing a resource, such as money, a skill, or a person.
contrast with 'resort to', which often has a more negative or desperate connotation; 'fall back on' suggests a prepared or reliable backup.
He fell back his family for help.He fell back on his family for help.the preposition 'on' is essential to complete the meaning of this phrasal verb.