I posted a similar question a few weeks ago:
https://forum.mrmoneymustache.com/ask-a-mustachian/early-termination-of-phone-contract-vs-sucking-it-up/msg165686/#msg165686. The first reply by I.P. Daley has a bunch of useful links to consider.
You should read those links in depth, but here are a few things you should consider:
1. What device are you using? Will you want to continue to use this device? Or will you have to buy a new device?
2. What will you have to pay to terminate your contract early?
3. What plan do you want to replace your current plan with?
Looks like you are on AT&T, like me:
1. If you want to continue using your device, it will limit the number of low cost carriers (MVNOs) you can use.
2. AT&T has an early termination fee of $325 per device (minus $10 per device for each month of your contract that you have fulfilled).
3. Look up MVNOs that are compatible with AT&T phones if you want to keep your device (you will have to ensure that AT&T unlocks the device when you pay off your contract).
Doing the math, let's assume you both go to a $40/month unlimited plan on Airvoice Wireless
https://www.airvoicewireless.com/PlansA.aspx:
Costs: New Phone service: $40*2*18 = $1440
Early Termination Fee: ($325*2) - (6*$10*2) = $530
Total = $1970
Savings:Old Phone service: 18*$125 = $2250
Total Savings: $280
It might be worth it to change plans now, but you won't actually see any savings for a while, since you will have to come up with $530 up front for early termination fees. You can save more money by getting a cheaper plan (i.e. cutting back on your data usage).