Guarantee Mortgage - San Francisco, 505 Montgomery

We have helped Bay Area families finance their home purchase, with over $2 billion in loans annually, and we can help you.

Offering a wide range of products and services, Guarantee Mortgage is well prepared to meet every real estate lending need.

We have 22 years under our belt providing world-class client service. Our top priority is to make sure you are presented with all available loan options, so that you can make an informed decision, that’s right for your financial situation.

Guarantee Mortgage NMLS #1850 and CAL-BRE License #01215943


Recommendations (914)

3 days ago

Karla Ramirez recommends Alberto R Zamudio

Store manager

Alberto helped me so much with my Refi process. He answered all of my questions and explained in detail something I didn’t understand. He is very professional and I would highly recommended him.
Jun 12, 2018

David Falconer recommends Ming Leong

Owner Falcon Properties

Ming has provided financing for my commercial and residetial properties for some 15 years. Dispite some significant barriers, like interest-only loans, he has always found a lender willing to finance my properties at attractive terms and conditions. Ming knows both what's possible and impossible in the lending market. And, he knows how to get the paperwork completed and loans in place.
Jun 9, 2018

Roey Rahmil recommends James W. Argo

First-time homebuyer

James was fantastic to work with. He and his team ensured that the transaction closed smoothly on a fast timeline. He was responsive, knowledgeable, diplomatic with the other side of the deal, and unfailingly honest with me. I recommend James wholeheartedly.
Jun 8, 2018

Beth Eichenberger recommends Orlando Diaz

Maternal Child Director

Orlando was great- He answered my questions day and night. H walked me through some areas of confusion and even sent in documents for me that I would not have been able to do in a timely manner. I would recommend him and Risa Meyer to anyone who was interested in financing or refinancing ther home.
Thanks to both of you.
Jun 6, 2018

Tobee V. recommends Orlando Diaz

Wholeheartedly recommend Orlando! He went above and beyond to help us with getting quickly and fully pre-approved and for us to subsequently close on our home. He made himself available outside of typical business hours when it mattered most.
Jun 6, 2018

Flor Melara recommends Alberto R Zamudio

Executive Producer

I started working with Alberto Zamudio about 3 months ago when my husband and I were in the process of getting approved for a new loan. At the time, our home buying situation seemed impossible, but thanks to Alberto and his guidance we were able to get the loan that was right for us. Through the process, Alberto was always in contact with us, either by phone or email, and kept us up to date with the loan. I really appreciate his help and I know that even now that we have our home, we can rely on his help and guidance because our relationship is just beginning. I highly recommend him and I know he will serve your needs in the most professional and efficient manner.
Jun 5, 2018

Mike Williamson recommends Aisling Ferguson

Aisling was great. Very knowledgeable with great resources! Will be back for the next round of financing
May 31, 2018

MP recommends Alberto R Zamudio

Cybersecurity Specialist

Alberto took time out of his weekend to meet with us. He was professional and explained the full process to us. As the process progressed he took the time to explain each step and what was needed. In getting to know Alberto a bit, it stuck with me that he cared about helping people achieve their dream of owning a home.
May 31, 2018

NANCY WALIA recommends Orlando Diaz

Mr. Diaz did a Refinance for in May 2018. The information required from me was sent over a secure transfer site. He was with me daily, letting me know what was additionally required to complete the package. He arranged for the Title Company Closer to meet me at a third party location to facilitate the final paperwork signing. I felt that he was at all times professional, knowledgable, and had my best interest throughout the process. I highly recommend him as your Loan Specialist, and his company, Guarantee Mortgage.
May 29, 2018

Scott Gross recommends Orlando Diaz


We had a very challenging loan given the unique ownership structure of the house. The underwriters required a huge amount of documentation to evaluate the loan application. Orlando painstakingly went through the process with us always looking for the optimum way to present our data in response to the underwriters requirements. He was responsive, efficient, TIMELY and thorough with followup.

What could have been a nightmare was made to be an efficient, professional process. He was at all times pleasant, patient and encouraging.

At the end, I told him that whatever he was getting paid it wasn't enough!!!

I would highly recommend him without hesitation.

May 22, 2018

Christopher Sichel recommends James W. Argo

Home owner

Jim is the BEST! Friendly, well informed and took excellent care of all of my needs! I highly recommend him!
May 15, 2018

Vanessa Carrington recommends Kathy Derangi

I feel so lucky to have found Kathy! She has been the penultimate professional having guided me through the entire process, communicating very clearly on what was needed, extremely helpful and friendly. She was always quick to reply with an answer or offer a solution.
I highly recommend her and am thrilled i never have to look any where else for my loan needs.
Thank you Kathy!
May 9, 2018

Grant Inaba recommends James W. Argo

Good Real Estate Team Agent

James is great with organization and communication. He keeps his clients up to date and informed about large and small improvements in their loan that can add up to a huge advantage in the competitive Bay Area Marketplace. Highly recommended!
May 1, 2018

Adrian recommends Ming Leong

We needed a loan to purchase a house without contingencies in order to be better positioned as a buyer and not be in an extreme rush to sell our other house. The loan Ming found us was much cheaper than a bridge loan, but it was difficult to secure. Ming walked us through the whole process and made sure nothing was dropped. Can't think of any big lending institution that would have done the same.
Apr 30, 2018

Taejoon Ahn and Jeannie Lee recommends Aisling Ferguson

Over ten years, Aisling has helped us with three houses, refinancing and countless offers. She has that rare combination of high level strategic problem solving and nitty gritty detail oriented execution. She’s clear and direct in her communication and most importantly, has the highest of integrity. Aisling is the best. Total pro.
Apr 26, 2018

Emily Farmer recommends Aisling Ferguson

Aisling is an absolute rockstar and a must when navigating the San Francisco market. She can find a solution to almost any problem. And she is extremely fast and responsive.

Aisling moved mountains to get me re-approved over Easter weekend for my dream home! I've recommended her to all of my friends looking to buy or refinance.
Apr 25, 2018

Brad Cohn recommends Aisling Ferguson

Global Executive Creative Director

Have you ever been to the circus and seen the person who's spinning plates? Well that's Aisling. Except she's not just spinning plates. She's also juggling. Chainsaws. And not just chainsaws... bowling balls. Like 15-16 pound bowling balls. I had the closing of the sale of my condo and the closing of the purchase of my new home 2 days apart. And it went off without a hitch and she didn't miss a beat. Aisling makes things happen!
Apr 24, 2018

Kara Thacker recommends Aisling Ferguson


Aisling is a absolute must for anyone buying or selling in the Bay Area. I have worked with a great deal of mortgage brokers since 1999 when I started selling real estate and she is by far the best I have experienced. She finds a solution to almost any problem that arises in a real estate transaction. She’s incredibly smart, fast and efficient and always makes sure the client is at the forefront and happy. I won’t recommend anyone else to my clients moving forward.
Apr 23, 2018

Sara Andersen recommends Kathy Derangi

Kathy was very responsive and attentive during our refinance. She gave us advice to improve our credit rating so we could get a better rate. Truly appreciate her expertise.
Apr 19, 2018

Romain Morley recommends James W. Argo

Project Management Leader

Jim made my wife and I feel important in a pretty overwhelming situation. Although compared to others our budget was smaller, Jim understood and appreciated that it was a big step for us. He offer sound advice and walked us through the process.
Apr 18, 2018

Daniel Bennett recommends Aisling Ferguson

Director of Product Management

We were introduced to Aisling less than 7 days before she had us pre-approved in time to make our first offer, and she helped us quickly work through the counter-offer process over the next few days as all our amounts changed. She was helpful, tireless, reassuring, always available, and answered all of my questions throughout the process. She was also extremely efficient, taking only as much time was necessary to help us move forward through each step without dallying, which was really helpful given how much we were trying to get done in such a short timeframe.

5 stars+++

Thank you so much Aisling!
Apr 16, 2018

Russell Kent recommends Aisling Ferguson

Software Architect

Aisling was on top of everything and did a great job guiding me through a process that was new to me. I wouldn't hesitate to recommend her.
Apr 16, 2018

Karen Mack recommends Aisling Ferguson

Aisling was referred to us through our agent. She was fantastic - spot on, diligent, and responsive. We definitely felt like we were in safe hands and highly recommend Aisling. Thanks for everything.
Apr 15, 2018

Carlye Mitryk recommends James W. Argo

Sr Project Controller

We loved working with Jim! Moving from Florida, we had no idea what we were getting into with the crazy San Francisco housing market. We heard from several people that it was key to have a local mortgage broker. We received the recommendation from our realtor (Jeremy Burnett, also amazing!) Jim took valuable time out of his day to teach us about the market and put us at ease. When we finally found our home of our dreams, Jim came through immediately and we were able to close in weeks! Couldn’t have done it with him!
Apr 9, 2018

Samantha Competente recommends Aisling Ferguson

Broker Associate

Aisling was super easy to work with and communicative during the entire escrow process. Look forward to working with her again!

Our Team

  • Aisling Ferguson

    NMLS #280915 Loan Consultant - San Francisco
    NMLS #280915 / 1850 - CA BRE #01225420 / 01215943

  • Debra Stedt

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #247657 / 1850 - CA BRE #00972315 / 01215943

  • Orlando Diaz

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #238849 / 1850 - CA BRE #01475255 / 01215943

  • Foster Weeks

    Loan Originator - San Francisco - Montgomery St.
    NMLS #253370 / 1850 - CA BRE #01383598 / 01215943

  • Natasha Lovas

    Senior Mortgage Advisor - San Francisco - Montgomery St.
    NMLS #239455 / 1850 - CA BRE #01161948 / 01215943

  • Kathy Derangi

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #1151839 / 1850

  • James W. Argo

    Senior Loan Officer - San Francisco - Montgomery St.
    NMLS #257031 / 1850 - CA BRE #00869591 / 01215943

  • Larry Horowitz

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #239001 / 1850 - CA BRE #01003870 / 01215943

  • Fif Ghobadian

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #110501 / 1850 - CA BRE #01394440 / 01215943

  • Robin Patronik

    Senior Loan Officer - San Francisco - Montgomery St.
    NMLS #241087 / 1850 - CA BRE #01347330 / 01215943

  • Allan McAllister

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #280540 / 1850 - CA BRE #01372084 / 01215943

  • Ken Dean

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #237940 / 1850 - CA BRE #0902556 / 01215943

  • Cecelia Tyeskey

    Sr. Mortgage Loan Consultant - San Francisco - Montgomery St
    NMLS #239861 / 1850 - CA BRE #01212004 / 01215943

  • Kevin Casey

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #238192 / 1850 - CA BRE #01178612 / 01215943

  • Risa J. Meyer

    Mortgage Specialist - San Francisco - Montgomery St.
    NMLS #332214 / 1850 - CA BRE #01126851 / 01215943

  • Ming Leong

    Loan Consultant - San Francisco - Montgomery St.
    NMLS # 252471 / 1850 - CA BRE #01369831 / 01215943

  • Alberto R Zamudio

    Sr. Loan Advisor - San Francisco - Montgomery St.
    NMLS # 282940 / 1850 - APMC CA BRE #01215943

  • Bob Siefert

    Senior Vice President - San Francisco - Montgomery St.
    NMLS #55105 / 1850 - CA BRE #00921214 / 01215943

  • Mireille Costandi

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #249322 / 1850 - CA BRE #01132350 / 01215943

  • Amy Lai

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #341535 / 1850 - CA BRE #01795977 / 01215943

  • Paul Rea

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #280163 / 1850 - CA BRE #00856755 / 01215943

  • KC Murphy

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #255492 / 1850 - CA BRE #1007053 / 01215943

  • Sally Adam

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #245703 / 1850 - CA BRE #01244582 / 01215943

  • Sheila Wood

    Manager/Loan Consultant - San Francisco - Montgomery St.
    NMLS #253742 / 1850 - CA BRE #00824166 / 01215943

  • Fe David

    Loan Consultant - San Francisco - Montgomery St.
    NMLS # 482592 / 1850 - APMC CA BRE #01215943