Military deployments bring transition into all areas of service members and military families lives, including their financial lives. There are those who face the wave of change head on by planning and preparing their money for their absences. Then there are others that don’t make preparing financially for deployments a priority.

Here are four big rules service members should follow. Breaking these could have disastrous effects on their finances while they are deployed.

1. Picking someone trustworthy to manage your finances.

Make it a priority to select someone who you trust to handle things while you are gone. Service members often have limited access to communication when they are deployed to foreign countries. It probably, then, is not wise to pick a new girlfriend who you have known for three weeks to be in charge of your money; I don’t care if “this time” it’s true love. Don’t leave her in charge of your livelihood.

2. Take preparation seriously.

Now is not the time to throw caution to the wind. Everyone in your chain of command takes the time to remind you to review your DD Form 93 and your SGLI beneficiary for accuracy for a reason. There’s a solid chance your terrible ex who drained your bank accounts and left town on your last deployment could still the sole person slated to receive the SGLI payout in the event of your death.

3. Arrange for your departure.

The weeks and months before a deployment is a hectic time filled with spending time with loved ones, doing predeployment training, and enjoying freedom while you still have it. Just make sure you also take the time to do things like inform your landlord that you are leaving, put your household goods in storage, and make sure you won’t be charged for your cell phone while you’re gone.

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4. Save your money.

One of the silver linings of being deployed is that you typically save money while you’re away. There are fewer things to spend money on, and combat tours come with benefits like hazardous duty pay and income tax exemptions. Don’t start spending money like you’re rich even before you leave the country. Learning you may be deployed is not a good reason to pick up all the bill for all the drinks at your Bon Voyage party. Not only is it unnecessary, if your orders get canceled or changed, which happens all the time, you’ll feel pretty stupid and broke.